Kosei

***DANGER! DANGER!*** This page may contain a lot of **spoilers.**
It's recommended you play Team Salvato's *Doki Doki Literature Club (Plus)!* and read/play *Re:Literature Club! The Doki Doki Virus*, *The Mystery of the Drama Club* (not created yet), *The Drama Club's Doki Doki CyberForce RPG* (not created yet) first before you read the article.

## Personal information

### Aliases

D-Ranger CyberGol-D
Dokiranger CyberGold
Kosei
コーセイ
Kōsei
コウセイ
Kousei
Light of Chaos
Light of Despair
Light of Hope
Light Star (光（こう）星（せい） *Kōsei*)
Sentinel of the Club Hub Worlds

### Affiliation(s)

Drama Club: Vice President, senior technician, and engineer
Drama Club's CyberForce: Mentor
The Duran Empire: D-Ranger
FORAD Corporation: Tech Researcher

## Physical description

### Eye color

Gold

***/ WARNING: SPOILERS /***
**Kosei** (コーセイ *Kōsei*) is the Vice President and a senior technician of the Drama Club as an engineer, a tech researcher of FORAD Corporation, and a Sentinel of the Club Hub Worlds. He has a younger sister in the Drama Club named Ayami.

## History

When Duran became the second Club President of the Drama Club, he assigned his Senior Technician Kosei as Vice President of the Drama Club.
### *The Mystery in the Drama Club*

There are currently no information on what Kosei did during *The Mystery in the Drama Club* but Duran believed Kosei told Duran who he really was either during the second-half of *The Mystery of the Drama Club* or at the start of their next game.

### *The Drama Club's Doki Doki CyberForce RPG*

***SPOILER WARNING: This story will contain some spoilers that will currently be exclusive on this wiki until it is written in fiction.***
After the destruction of Doki Doki High School when the Phantom Killer Duran became Cyberlord Duran, Kosei brought the surviving Drama Club members to one of his secret organizations called CyberForce Network Security. However, the headquarters for CyberForce was also attacked but some CyberForce survivors including researchers and a few soldiers remained and half of the CyberForce DigiChangers, Model: Heart was stolen by the Cyberlord. Kosei trained the Drama Club members to become digital warriors known as Digirangers.

Sometime after the new Digirangers graduated their training and were given their CyberForce DigiChangers, Model: Heart, Kosei made former Weightlifting Club President Ryoku the leader of the team while Bakudan took second-in-command when their mentor and commander Kosei stays out of action. Cyberlord Duran began his next attack. The new Dokirangers go into action with their new powers. When Cyberlord Duran discovered a new team of Dokirangers, he attempted to brainwash them to his side. However, Kosei went into action as Dokiranger CyberGold ("Light of Hope") and Kosei was the one who fell victim to the Cyberlord's mind control. Kosei's younger sister Ayami was saddened but she'll do what it takes to get her brother back.

Ocassionally, the "mind-controlled" Kosei battles against the Dokirangers as the Cyberlord's elite warrior called D-Ranger CyberGol-D ("Light of Despair"). Cyberlord Duran "modified" the CyberGold DigiChanger, Mode: Heart, into a more powerful but corrupted version.

In one of their later battles, Duran and Kosei captures Aika and while Aika struggles to fight back, Duran ordered Kosei to kill Aika. Using CyberGol-D's RadiantDeath giga attack, Aika's body glowed and an explosion occurred. From the high grounds, Aika fell down and Ryoku catches his girlfriend in his arms, lifeless. Ryoku's and the other Digirangers' hatred for Duran skyrocketed while Kosei's younger sister Ayami was emotionally stressed and saddened.

#### Kai's invasion in the Drama Club Hub World

Near the end of the game when the Digirangers had their final battle against Cyberlord Duran and when Kai invaded the Drama Club's Hub World, corrupting their game, Cyberlord Duran and Kosei end their charade and they teamed up with the Digirangers to defend against the new mysterious threat that threatens their world.

At some point of Kai's and Koshiro's invasion on them, Kosei disappears but he tries assisting everyone else from behind-the-scenes. However, one-by-one, the Digirangers and Cyberlord Duran were being infected by the Doki Doki Virus one-by-one until it was just Ayami left. Kosei tried his best to protect Ayami from the invasion but ultimately failed to protect his younger sister.

#### The aftermath

After Kai and Koshiro gave up searching for Kosei, Kosei started losing all hope and went into despair but he found Ayami's damaged scarf that Kosei gave to her on Ayami's 14th birthday four years ago. One-by-one, Kosei discovers that other Club Hub Worlds were being attacked and figured out that other Club Hub Worlds were attacked by Kai. By the time Kai reached the Literature Club Hub World (only two clubs left but the Shogi Club was taken during the Literature Club's invasion), Kosei stopped hiding and finally acted, entering the Interdimension between the Belief Club, Debate Club, Literature Club and Shogi Club undetected and disguise himself as an "infected" Cyber Security Ranger.

### *Re:Literature Club! The Doki Doki Virus*

When the KaiserFever Deviranger team defeated the Literature Club Dokirangers and escorted the Literature Club members to the Ritual Chambers to convert the Literature Club members into Belief Club members, Sayori tripped and she was "mysteriously" infected with the Doki Doki Virus. Below Sayori was **Kosei** in his Cyber Security Ranger uniform as he planted a microscopic version of the Doki Doki Virus in Sayori. When Kai found out Sayori was infected with the virus after her conversion, he sent the Devirangers and Infected Cyber Security Rangers to search and contain Infected Sayori.

When the Infected Cyber Security Rangers, Infected Ryoku, and Infected Bakudan found the Literature Club members outside their room, they tried destroying a barrier that Infected Sayori casted over them while Infected Sayori was mentally torturing Monika. After busting through the digital force fields, while they secure everyone, Infected Sayori escapes. While Infected Bakudan and many Infected Cyber Security Rangers continue their hunt for Infected Sayori, Infected Ryoku and a few Infected Cyber Security Rangers (including Kosei who is undercover as "Infected Cyber Security Ranger C") stay to guard the Literature Club members until they can figure out what to do with them. Infected Ryoku goes out to find a new room for them.

Infected Sayori returns to defeat the guards and infected Main Character 1 with the Doki Doki Virus. Infected Ryoku returns and stuns Sayori with his gravitational powers while Infected Cyber Security further immobilizes Infected Sayori. However, one of the "Infected" Cyber Security Rangers turned out not to be infected and cured the Literature Club members from the Doki Doki Virus. Figuring out there was a traitor, Infected Ryoku discovers this security ranger to be Kosei, who survived the Drama Club's invasion.

Kosei changes into his Dokiranger CyberGold form to deal with Cyber Security. Once club administrative reinforcements arrived and when Kosei reveals that he is a Sentinel of the Club Hub Worlds to the club administrators, giving them orders to rescue everyone, Kosei and Cyberlord Duran team up against Infected Ryoku. Infected Ryoku demanded Kosei to battle him with CyberGol-D as Infected Ryoku wanted to defeat Kosei while he's in that form. Infected Ryoku still held a grudge during their battles in their RPG when a "brainwashed" Kosei "killed" Ryoku's girlfriend Aika with CyberGol-D's RadiantDeath giga attack. However, Infected Ryoku was defeated and Kosei cured him.

Kosei then teamed up with Martial Arts Club President Ryo (a Ryujutsu Master) to defeat Infected Aika and cure Aika of the Doki Doki Virus, then he aided Cyberlord Duran and Dokiranger CyberPink Ryoku in battle against Infected Bakudan. Infected Bakudan was cured of the virus when Duran used one of Koji's DDVaccines to cure Infected Bakudan.

Kosei then assisted Music Club President Yumi (a Music Goddess) and Anime Club President Kenta against Infected Denki and an army of Category:infected students. Denki was cured and Kosei went ahead, battling Infected Ayami, who was emotionally enraged at her older brother for abandoning her and making her alone on a team yet again. Kosei defeats his infected younger sister, cures her, and apologized to her when she woke up. Kosei gave Ayami her scarf—all fixed. Kosei leaves Kenta and Yumi in Ayami's care while he progresses forward.

There was a huge horde in this one hallway for a protective reason so Kosei was searching for a room that Kai and/or Koshiro was trying to block. Kosei also noticed that Infected Cyber Security Rangers have not been around since Kai doesn't want to take any chances of them being cured by a vaccine. Kosei nearly gets surrounded by a group of infected students and he ducks into the men's restroom and sets up a barrier so he doesn't get trapped. However, there are new types of viral enemies lurking in the restrooms.

Koji calls Kosei and tells Kosei that there is something strange north of the men's bathroom but Koji likely won't get any reception. Kosei blasts a hole in the restroom wall and enters a pitched-black room that seems to be a wrecked library. It's quiet in here except for some hisses. Kosei uses his CyberGold class in this area and uses PhotonSaber as a light source since it gives off the brightest light. We help Kosei guide through this dark maze and something strange attacks and jumpscares us. It appears to be a giant serpent-like creature. Kosei cannot see to fight this mysterious enemy and he eventually demorphs after being defeated by this horrifying creature. Kosei switches to his Cyber Security Ranger class and we guide him through another door, which Kosei blasts open and enters it before the creature that was pursuing him catches him.

Kosei enters another pitch-black room, one that he is not familiar with. We are once again guiding him through this pitched-black room as he switches back to his CyberGold class, using his PhotonSaber skill. The mysterious snake-like creature followed us in this room and this room smells like blood. It's a torture room with cages. Kosei gets into a shock trap that Koshiro set and Koshiro reveals himself and takes some of CyberGold's data, then flees so that he doesn't get involved with the "snake". Kosei frees himself but he is attacked by the mysterious creature and was pushed into another room, one that is much brighter and more cybernetic. Now that we can see the giant yellow serpent-like creature, Kosei tries fighting back. Kosei tries using the VaccineBuster on the creature but it didn't work.

The mysterious snake is then attacked by waves of green energy outside the room, which was done by Cyberlord Duran. The Literature Club and the Drama Club members join forces together. The Literature Club members transform into their new Tokuranger classes and the Drama Club members transform into their signature Dokiranger classes. The special classes the Literature Club members have are Tokuranger CyberKnight (previously used by Ryoku, currently used by Main Character 1, data originated from King D-Templar), Tokuranger CyberBeast (previously used by Aika, currently used by Natsuki, data originated from Feralimon), Tokuranger CyberTech (previously used by Bakudan, currently used by Erika, data originated from Dr. Mu), Tokuranger CyberMage (previously used by Ayami until it broke, currently used by Main Character 2 after it was repaired, data originated from Pandora-D) and Tokuranger CyberNinja (previously used by Denki and Ayami afterward, currently used by Yuri, data originated from Yorushi). Meanwhile, Sayori has a supporting class called Cyberlady Enchantress while Monika has a battle class called Cyberlady General and they are now auto-battling allies just like Cyberlord Duran.

Before we could battle the monster, Kai calls the monster to retreat. The giant-snake like monster demorphs into what appears to be an Infected Isshin carrying a portable torture device. Infected Isshin teleports out of the area. Turns out the reason why Kosei's vaccine didn't work on him was that Kai re-coded his Doki Doki Virus to counter the vaccines.

Kai then calls forth a new team of Devirangers which include Datanoid versions of the standard Devirangers plus the new Deviranger ViralGold, who has a modified version of Kosei's Dokiranger CyberGold powers. In addition to these viral Datanoids, there are also six new Devirangers that are based on "unused" powers of the Drama Club. These other new six Devirangers are actually avatars of the Debate Club Vice Presidents as well as Akida (as Deviranger ViralPurple) and Takeru (as Deviranger ViralSilver). Rather than battling the Literature and Drama Club CyberForce teams, they stall out while Kai is working on his final defense project until Aika takes action.

### Preparing End Game... Return of the Deathcube

To stall out the Literature and Drama Club members even further, Kai warped the empty digital room into the Deathcube with everyone separated. While we start off with Kosei, we can switch between any one of our playable Digirangers and help them guide them out of the Deathcube while defending against possible traps, the Devirangers, and at rare times, Infected Isshin (Virus Fever Mode) as a random boss encounter.

Once everyone escapes the Deathcube, they meet up in one dark area and Kai is preparing his final experiment, the TeraKaimera, which is an amalgamation of the Doki Doki Virus Core and all infected characters with the powers of the Devirangers added to it. If Infected Isshin wasn't defeated in the Deathcube, he becomes part of the TeraKaimera as the amalgamated creature's snake tail. If Infected Isshin was defeated in the Deathcube, the TeraKaimera is in its weaker form as TeraKaimera -incomplete-. All of our party members must stand together to defeat this monstrosity but all of our powers aren't enough.

Furthermore, Kai is giving it his all by infecting himself with the Doki Doki Virus, becoming a "super demon", and fusing himself with his amalgamate experiment, becoming a giant black scorpion-like creature. However, Koshiro had enough of Kai's recklessness that he was secretly creating a program to steal Kai's Belief Club Hub World Administrative Privilege. Infected Kai defuses from his experiment, becoming a mere infected "demon" and he is angry about Koshiro's betrayal. With the Belief Club fully in Koshiro's command, Koshiro commanded the TeraKaimera to swallow Infected Kai and finish off everyone until new Cyber Security reinforcements arrive.

Kojima, the father of Koji and uncle of Kai, came through with the supercomputer recovered and Kojima sent the S-Squad Cyber Security Rangers into action. The S-Squad Rangers will hold off the TeraKaimera and free everyone that is part of it while the Literature and Drama Club members go after Koshiro. The S-Squad Captain gives Kosei a Revoke program that will disable Koshiro's Club Administrative Privilege. With Koshiro having Club Administrative Privileges to both the Belief Club and Debate Club, Kosei will have to use it twice but there is a cooldown to the Revoke program.

Several victims of the TeraKaimera were freed including two Sentinels: School Principal Dan Takashima (who is very angry about everything that has happened) and Koji's Vice President Satoshi, who will temporarily aid us in the final battle while Koji assists the S-Squad Rangers.

We encounter Koshiro and while he despised Kai's latest strategies, Koshiro had no choice but to go all out as well, infecting himself with the Doki Doki Virus and entered Virus Fever mode. He also added the powers of his Infected Koshiro (Virus Fever Mode) would have the power to destroy the digital world and the first thing he did was damage all of the character's back-up bio-data files in the *Club Hub Worlds*, meaning that once any of our party members' LE reach 0, that character will actually stay dead but in addition to that, we will lose connection to them (meaning that if anyone dies, it is a Game Over). However, we have additional battle assistance from the Club Presidents who previously assisted us. Kenta, Ryo, Yumi, and Takeda (who was recently rescued), aid us in the final battle and their files are not affected.

During the final battle, all of the Club Presidents start off with their strongest assists, several of them we assist them in to deal damage to Infected Koshiro (Virus Fever Mode) and power-up our party members. Our game starts to glitch too during this battle and eventually, our new allies' back-up files will be damaged and if we lose them later in the fight, it will result in a Game Over. After dealing enough damage, Kosei activates the Revoke program and Koshiro's administrative privilege in the Debate Club was removed but Koshiro still has administrative privilege in the Belief Club. At some point, Infected Koshiro (Virus Fever Mode) figures out that the TeraKaimera is defeated by the S-Squad Rangers and with most of the infected characters being freed, Infected Koshiro (Virus Fever Mode) felt weaker. Infected Koshiro (Virus Fever Mode) flees from the final battle to deal with the S-Squad Rangers.

We return to assist the injured S-Squad Rangers against Infected Koshiro. Not only us but the Debate Club Vice Presidents who were freed from the TeraKaimera\* assist us to defeat Infected Koshiro. With the help of Koji modifying the Debate Club's game's gameplay mechanics, the Debate Club Vice Presidents start a Debate Poll game to demote and delete Infected Koshiro. Infected Koshiro cannot do anything to stop it except voting himself to not be demoted or deleted but everyone added their votes to demote and delete Infected Koshiro. The final results: Infected Koshiro had his Club Administrative Privilege of the Belief Club revoked, then he was deleted from the field.

#### The aftermath

After everyone was safely rescued, everyone returned to the Nexus dimension from the Digital World. Drama Club President Duran and his Vice President Kosei stopped by at the Literature Club. Kosei thanks the Literature Club members for their help and apologize to them, especially to Sayori for using her and the damage her infected self caused to Monika. Aika, who still held a grudge on Duran and Kosei for what they did to her back in their RPG, was chasing Kosei and Duran down the halls and found them in the Literature Club, chasing them out of the Literature Club and Duran and Kosei high-tailed out of there.

## Playable classes

*The Drama Club's Doki Doki CyberForce RPG*

* Dokiranger CyberGold (starter class)

*Re:Literature Club! The Doki Doki Virus*

* Cyber Security Ranger (starter class)
* Dokiranger CyberGold (first unlockable playable class)
* D-Ranger CyberGol-D (second unlockable playable class)

### Dokiranger CyberGold

*Main article: Dokiranger CyberGold*
**Dokiranger CyberGold** is an advanced Digiranger class of the Heart Models imbued with the **Power of Light**. It is activated and equipped over a user when the user calls out the transformation call "CyberForce Emergency! Dokiranger CyberGold!" while holding the CyberGold DigiChanger, Model: Heart. Dokiranger CyberGold's motto is **"Light of Hope!"** (希望の光！*Kibō no Hikari!*).

Kosei used this class until he was captured by The Duran Empire and had his DigiChanger "modified", becoming D-Ranger CyberGol-D.

### D-Ranger CyberGol-D

*Main article: D-Ranger CyberGol-D*
**D-Ranger CyberGol-D** D（ディー）・レンジャー・サイバーゴール・D（ディー） is an "evil" modification of Dokiranger CyberGold. Like CyberGold, it is empowered with the **Power of Light** but the "light" that CyberGol-D has is "darkened," being called the **power of chaos** or **chaotic light**, combining the powers of Light and Virus. Compared to CyberGold, CyberGol-D has stronger destructive light abilities but they may put the user or others at risk. This class has the power to instantly kill any victim (at a chance) with a single touch via RadiantDeath. D-Ranger CyberGol-D's motto is **"Light of Despair!"** (絶望の光！*Zetsubō no Hikari!*).

D-Rangers are an advanced variation of Digirangers used by The Duran Empire in *The Drama Club's Doki Doki CyberForce RPG* and are said to be stronger than Dokiranger CyberColor classes. While it initially serves as a boss class against the heroes, it later becomes a temporarily playable class in *The Drama Club's Doki Doki CyberForce RPG* and a fully playable class in *Re:Literature Club! The Doki Doki Virus*.

### Cyber Security Ranger

*Main article: Cyber Security Ranger (class)*
An Energy-elemental class. Being a Sentinel of the Club Hub Worlds and the digital world, as well as working for FORAD Corporation, Kosei also has access to the powers of FORAD Corporation's Cyber Network Security Force. Cyber Security Rangers are guardians and enforcing soldiers of the digital world. They are equipped with anti-club administrative gear to arrest and nullify rogued Club Presidents and they have some small resistance to Viruses.

## Trivia

Kosei's name when written as 光（こう）星（せい） (*Kōsei*) translates to "light star".