Sachi Mizuiyama

**Spoiler warning: *Plot and/or ending details follow. Read at user's own risk!***

## Personal Status

### Participated

* Takeda Haunted Mansion Case
* Museum of Medieval Torture Case
* Libra Girls Academy Case

## Debut

### Novel

*Danganronpa Kirigiri* Volume 3

**Sachi Mizuiyama** (水井 山 幸) is a character featured in *Danganronpa Kirigiri,* debuting in the third volume and became a reccurring character in the following novels.

Sachi is a 7th-rank detective specializing in technological crime and also specializes in architecture, as the first two digits of her number speak of - DSC 527.

She was one of the few detectives summoned to take part in the Duel Noir at the Takeda Haunted Mansion. Afterwards, she was recruited by Kyoko Kirigiri in order to help defeat the Twelve Zodiac Duel Noir Challenge, with her taking on the Museum of Medieval Torture Case.

## History

### Prior Life

 Prior to becoming a detective, Sachi was originally a school counselor at St. Anne's Academy thanks to her ability to read people. During that time, she got into an altercation with one of the students Hana Takezaki, and eventually left. Sachi became an architect following leaving St. Anne's, though later on she registered into the Detective Library, specializing in architecture since she found buildings to be much more interesting than humans. However, during this time the Victims Catharsis Committee approached her and she would take up a Duel Noir against her old student as the culprit of the Libra Girls Academy case.

### Danganrinpa Kirigiri Volume 3

#### Takeda Haunted Mansion Duel Noir

She is called to the Takeda Haunted Mansion Duel Noir, on January 10th, alongside fellow detectives Hajiki Yaki, Salvador Fukuro Yadorigi, Korisu Kakitsubata, and Suntetsu Shirasu, with her letter asking her to check the architecture of the building. When the proxy no-shows, four of the five (except for Suntetsu) confess their true professions after a deal of time had passed and decide to wait it out while there. During that time, Suntetsu is murdered in a locked room manner, though initially, it takes the arrival of Kyoko Kirigiri and Yui Samidare to discover that fact since the door had been rendered shut by use of rubber bands preventing the door from opening. When the police arrived, Sachi was in solidarity with the other three detectives that she met with by omitting her profession, knowing the police and detectives didn't quite have a cordial relationship.

During the investigation, Sachi assists by handing over her letter that she recieved before being the first one to be interrogated by the police. Once she was let out, she revealed her profession and standing to Yui and Kyoko. Sachi initially believed the case might have had something to do with religion since it was Suntetsu's specialization, though was still as baffled as most concerning how he died, with her suggestion of the killer escaping in the blackness of the dojo being refuted by Hajiki (who had fallen down during his attempt at opening the door).

For Sachi's alibi, she spent 3PM onwards in the common room reading a book, noting how everyone else was walking out and about, but she pretty much stayed in one spot. She did meet Suntetsu when he sat down to use his phone, the monk claiming that he was trading stocks. Sachi is initially fingered as the culprit behind this Duel Noir (under the belief that only someone of Sachi stature could have squeezed in the small gap of the dojo's doors to kill Suntetsu and get out) and is arrested, with Sachi protesting such treatment heavily. In reality, this was merely Kyoko's way of deceiving the true culprit,  Korisu , into revealing herself. However, Sachi would only learn of this later on and would still hold a grudge against Kyoko leading into the next day.

### Volume 4

#### Twelve Zodiac Duel Noir Challenge

The next day, she is called out by Kyoko to the train station under the assumption that since she, alongside Hajiki and Salvador, was the third parties in the last Duel Noir she had no connection to the Committee and could be trusted. Sachi was wary of this and hid nearby, watching with binoculers, until Hajiki and Salvador revealed themselves. When she revealed herself, when all four were about to leave in Salvador's car, she let it known she still held animosity towards Kyoko for having her falsely arrested until it was pointed out that she would have been framed for real if the culprit's plan worked. As such, she backs down and calms down further whilst talking with Salvador, the two clearly taking a liking to each other.

During the ride, she listens in on Yui's and Kyoko's request for assistance and initially doesn't want part of it since she doesn't specialize in homicides. However, after both Hajiki and Salvador agree, she gives in to the pressure following Kyoko wanting only teammates to continue hearing the rest of it, though claims its to help her pride after being falsely arrested. With the team formed, she requests that they pick a Japanese sounding name, before Kyoko pushes the group to choose a Duel Noir. For this, she chooses to challenge the Museum of Medieval Torture Case Duel Noir, since she has been to the museum before and is familiar with it. When the group chooses to call Yui at certain time intervals, Sachi took the 12:30 time slot.

### Volume 5

#### Museum of Medieval Torture Case

Arriving at the museum, she is surprised by the place being open since it was previously closed as a result of its creepy atmosphere that unnerved nearby home owners. In the past, she asked to review such a location for it to be refurbished before it was decided to shut it down. Arriving on the scene, she lies about being the wife of a researcher there and is able to act in order to get more information. Thus, learning that the victim was Fukuju Idogaki (who worked for the nearby university) was dead in a nearby cottage next to the university and there was a fire there that charred the victim's body (even though the murder weapon as listed as an iron maiden).

Needing more information, she tracks down one of the students of Idogaki by the name of Katana Shindo. From him, she learns Idogaki was rumored to be a plagiarist who copied his own student reports and even murdered a researcher of his when she was going to expose him. She is then directed to meeting Kariyasu Karasuba at a nearby cafe, however, before that can happen, she runs into Licorne who warns her not to go overboard before disappearing. Sachi moves past the encounter and talks with Karasuba.

There she learns that Karasuba used to be lovers with a girl named Shoko who was the researcher killed by Idogaki, and over the course of talking with him it becomes clear he is the culprit with his birthday being August 30th, thus making him a Leo and the culprit of this case. However, she doesn't stop there and goes back to the museum to figure out the trick to the case, breaking into the museum with her pipe.

#### Goodbye BAR Case

 Later, Sachi meets with Hajiki, coming by to check in on the bar. When Hajiki explains the situation, she then points out that he had completely missed the culprit. It was as follows: what was going to kill the victim was the poison coated on the knife that lodged in his back, since he needed him to die at a set time. The knife was hovered over the victim using rope one wouldn't see due to the darkness of the bar, and the fact that most wouldn't normally look up. The knife would fall when the end of the rope tied to the door would be opened, which disheartens Hajiki since it was his breaking into the door that resulted in what happened to Katsumi. In addition, the culprit would be Gunzō who would probably be cleaning up the crime scene at the moment. When Hajiki realizes this, he thanks Sachi and invites her to come stop them. She agrees, but as soon as his back is turned, she bludgeons him in the head with her pipe. He survives the initial blow, but she kills him with another blow to the head. With Hajiki dead, she moves forward to her own Duel Noir at the Libra Girls Academy.

#### Libra Girls Academy Case

 Her Duel Noir involved the kidnapping of two other students, Nazuna Tōakitsu and Tsukiyo Nada, as well as killing Hana Takezaki as well. When Yui arrives, she disguises herself in a Black Cape and briefly knocks her out, waiting long enough for her to awaken before leaving in order to lead her into her trick to trap her. Her Duel Noir operated by use of modified rooms acting as scales, however, eventually, Yui was able to figure it out and the arrival of Salvador freed Yui's group. Sachi retaliated by bludgeoning Salvador with her pipe before the four of them could escaped, before trying to flee. Ultimately, the fitter Yui ended up subduing her and learnt about the truth of Sachi being the culprit of Libra Girls Academy. Sachi then held up Yui up with a nail gun. She explains she used to work at St. Anne's and took up the Duel Noir against her old pupil, but notes that was all in the past. Sachi knows she lost her Duel Noir now, but she could at least get Yui to fail.

She also reveals her devotion towards Gekka pushed her to go against Yui, with her not wanting him to step down as a head of the Victims Catharsis Committee. She finds that Gekka is the ideal when it comes to 'conviction' and is obsessed with him, to the point she feels that interfering with the challenge to make him the victor was her way of 'saving' him - a hero who has saved others, but no one has saved him. When Yui asks if her being at the Takeda Haunted Mansion was a set-up, Sachi notes it was probably Gekka's doing. She claims that even if she lost her Duel Noir, she still could have tampered with the bar and museum cases to make them unsolvable. Sachi also reveals that she had murdered Hajiki to Yui, much to the latter's dismay. During the conversation, both Nazuna and Tsukiyo carry out Salvador's body away, but since Yui was her target, she decided it was fine to let them go. She intended to hold Yui at the academy to make the time limit for the challenge run out, with only small breaks for food and to use the bathroom (though warned those could be revoked if Yui acted up). The interference of the Myst'ry Research Society that Salvador brought with him ruins such plans, with their weight combined tilting the scales and allowing them in her room. She tries to kill them, but they manage to knock her out and it leads to her being arrested.

### Sachi's Fate

 Later on, Sachi calls Yui from jail thanks to Gekka's having arrangements for it by having an officer give her a cell phone. With the intentions of being honest, she gives up the information regarding the Duel Noirs both she and Hajiki were assigned to. With her Duel Noir, she reveals that Kariyasu killed his target by angling the sun rays via the knights shining armor from the museum to an ice sphere that was on his iron maiden to focus the rays on the cottage. A fire would then break out, which would kill Idogaki (who he got blackout drunk the night before). When Yui questions why she was giving up this information if her intention was to ensure Gekka is the victor, Sachi says there was a small part of her than wonders if perhaps what Yui was doing was the 'Catharsis' that Gekka needed. Noting that it was likely they would never speak again, she hangs up to await her fate under the law.

## Skills & Abilities

### People Analysis & Deception

Sachi holds great skills in reading people, able to easily gauge their emotions to even their intentions. While it was a trait that previously allowed her to be an effective counselor, it also serves her well as a detective as she is able to navigate various social interactions and adapt accordingly. Sachi is also adept at lying, capable of acting even without preparation to the likes of police and enemies with a great deal of ease.

## Appearance

Sachi is a young woman with yellow-orange eyes, has long dark purple hair, and has very pale skin.

She wears a kimono and also wears glasses. According to Yui, she is miniature and because of this height, she can be mistaken for a child, but with the face of a beautiful intellectual.

## Personality

Sachi comes across as intelligent and elegant, serving as one of the more sensible of the detectives during the haunted mansion case. Sachi has major pride in her Japanese heritage to the point of wearing a kimono during her work and when joining forces with Yui, she suggests they pick a Japanese name. However, she isn't above holding a grudge for slights since she keeps one against Kyoko and the police following her arrest, keeping such grudge despite eventually knowing it was to catch the real culprit, and only dropping it following a reminder she would have been framed for real (with some minor acts of payback towards officers during the museum case).

 This unwillingness to let go of a grudge may have potentially led her to take up the Duel Noir to kill a student of hers back when she worked as a school counselor.

She's also a fairly cautious individual and doesn't usually want to take risks with her life at stake, like when she initially refuses to take part in the effort to stop the Duel Noir. Because of this cautiousness, she is even willing to lie if she doesn't feel it is safe and is fairly skilled in it. Despite this, she tends to be rather flustered when caught off-guard or put in a heavy situation, as well as caving when peer pressure is on her. She claims that assisting Yui's team will help her regain some pride after being humiliated following her fake arrest. She is also quite skilled at reading people and the environment, allowing her to easily be able to acquire information as need be. However, she prefers to inspect buildings instead, finding them far more interesting to read.

 She was someone incredibly devoted to Gekka and didn't want him to be defeated by Yui. It was to the point she was willing to kill, hurt and sabotage people in order to do it, holding no remorse for her actions. When found out, she holds an aggressive demeanor towards Yui and doesn't care about losing given she could still help Gekka. It's implied she was also doing this as a result of being jealous and bitter of Yui being chosen to challenge him, in addition to a desire to see Gekka saved himself. She also confesses to lacking the conviction of upholding justice compared to Gekka, though finding said conviction in the Executive is what resulted in her becoming obsessed with him.

### Yui Samidare & Kyoko Kirigiri

During their first meeting, Sachi presented herself as one of the more cooperative detectives, willing to share information with the duo if need be. However, she was left feeling utterly humiliated and bitter following Kyoko getting her falsely arrested, even if it was a ploy to bring out the true culprit (thus leading the grudge that lasted until the next day). Sachi was fairly cautious concerning Kyoko's recruitment call, to the point, she showed up early to hide herself to see what might happen. Ultimately, despite her initial misgivings about joining in on the challenge, she seemingly grows past it to aid them (if only to restore her pride).

 However, in truth, Sachi was a Victim herself and thus, she was their enemy. Sachi would do anything to ruin the challenge so that Gekka could come out on top, even if it means murdering those outside her targets or holding up Yui at her own Duel Noir. She dislikes Yui in particular due to not only her endeavor, but heavily implied to be jealousy from not being chosen herself. Still, following her arrest, she complies in giving up the information of the Duel Noirs of both herself and Hajiki. Ultimately, she does admit to Yui that a part of her wondered if what Yui was doing was the right move instead.

### Salvador Yadorigi Fukurō

Initially, their relationship seemed to merely be on neutral terms back during the Takeda Haunted Mansion case. However, the following day when both were recruited, Salvador also showed an interest with her, openly calling her a beauty (which caused her to blush) and being the one to calm her down from being mad at Kyoko for framing her. During the car ride, both seemed to share an interest in each other and were even about to schedule an outing together, prior to Hajiki interrupting them.  However, despite their seemingly mutual attraction, it did not stop Sachi from brutally hitting Salvador in the head with her pipe and hospitalizing him. Suggesting either she was faking her feelings for him, or her devotion to Gekka was stronger than her crush on Salvador.

### Hajiki Yaki

Initially, both were just unrelated parties called to the Takeda Mansion. Upon witnessing Sachi being the 'culprit' Hajiki looked flustered and commented that women could be scary. However, he would learn the truth later on. Once both joined Yui's team, their relationship seemed a lot more friendly, with both getting into discussion about the name of their new team, with Sachi requesting Hajiki choose something Japanese.  However, Hajiki was unaware of her true devotion to Gekka, and thus had his guard down when he met up with her whilst on the trail for the culprit of his Duel Noir. While Sachi was willing to explain how the case worked, she was utterly determined to ruin the challenge and willingly killed Hajiki the moment his back was turned to her.

### Licorne

Sachi met Licorne during her investigation into the Museum of Medieval Torture case. Licorne gave a warning for her to not go overboard, since he knew that the others on Yui's team would not want there to be anymore victims. After he disappeared, Sachi was left confused, wondering if Licorne was an agent sent by the Committee.

**Victims Catharsis Committee**

### Gekka Ryūzōji

 Like many detectives, Sachi revered Gekka for his work and heavily respected him. However, with Sachi, as someone who proclaims she lacks conviction, she found Gekka to be the epitome of the ideal, becoming obsessed with him. It was to the point that even after learning he was an Executive of the Victims Catharsis Committee, she was willing to kill and hurt anyone that could threaten to topple him. This was due to mostly believing that him remaining on the Committee was a way to save him (given that he saved so many himself, but noted no one did the same for him). Once she's imprisoned, Sachi gives up the information concerning the museum and bar, finally admitting to Yui that a small part of her wondered if being stopped was truly the 'catharsis' that Gekka actually needed.

## Trivia

* Sachi is the only known detective to be registered in the Technological Crimes section.
* Sachi holds the distinction of being the first Victim of the Duel Noir to also simultaneously serve as one of the Innocent for another case (to be exact, the scapegoat for it).
* When sitting in Salvador's car, Sachi prefers to sit seiza style.
* Likely as a nod to Salvador and Sachi's liking towards each other, both DSC numbers (752 and 527, respectively) are an anagram of each other.