Redback spider devices

The **redback spider devices** are a series of technological inventions created and used by Enokida that appear similar to their namesake in size, shape, and color. Though primarily serving as intelligence-gathering tools, some are also small-scale offensive weapons. So far, everyone except Zenji Banba has shown disgust toward the devices' design.

The redback spider (*Latrodectus hasselti*), also known as the Australian black widow, is a venomous spider that can be found throughout Oceania, Southeast Asia, and Japan. The Tokyo metropolitan government puts out a warning about redback spiders in the summer months, advising residents to be mindful of it inside of homes and buildings and warning of the effects of its bite, which often include sweating, nausea, vomiting, and skin irritation. An antivenom exists, and the spider is considered harmful but not deadly to humans. It is a member of the widow spider family, and the females are recognized by the bright red stripe on their otherwise black bodies, as well as an hourglass-shaped red mark on the underbelly.

## List of devices

*Known devices are listed in order of appearance.*

### Listening device

The original **redback spider listening device** (セアカゴケグモ型盗聴器, *seakagokegumo-gata touchouki*) is first introduced in volume one, second inning, and episode one. It is equipped with a microphone and GPS transmitter, and aside from its plastic body and small power switch, is almost indistinguishable from a real redback spider. Three devices are seen in the first light novel. Enokida offers one to Banba, who accepts it and shows it off to Yamato Igarashi and Genzo Gohda, wondering why the device could not be better camouflaged. He later attaches it to a sleeping Xianming Lin, and after following him, moves the device from Lin to Hisashi Ivanov's body. Through it, they overhear a conversation between Ryuuji Munakata, Reiko Asakura, and Yusuke Harada that identify Yusuke as Qiaomei Lin's killer. When confronted by Munakata and Reiko later, seeking information on Ivanov's killer, Enokida drops one in Reiko's jacket pocket and uses it to track her movements to Yusuke's apartment. The third is given to Lin by Banba when Lin poses as a human trafficking victim. Banba instructs the younger hitman to call his name into it if he needs help, and Lin uses it when their plan falls through.

Enokida later introduces the **redback spider listening device version 2.0** (セアカゴケグモ型盗聴発信機, *seakagokegumo-gata touchou hasshinki*) in the second inning of volume two. There is no noticeable physical difference between versions 1.0 and 2.0, but José Martínez explains to Lin that this version can stick to walls. In the second light novel, Enokida gives one to Martínez, who later attaches it to the back of Abe and Yamamoto's van in order to hit it later. Yamato also has one, which he drops in Abe's pocket when he steals his wallet so that he can return for more money.

In the third light novel, Enokida gives one to Feilang, who puts it on the sleeve of Lin's shirt in order to track him down after their first reunion. In volume four, the informant gives one to Lin when the two swap clothes, and Enokida and Banba use it to track Lin's location to Irasawa's garage. Jiro Tanaka plants one on Misaki Tanaka in the fifth light novel and traces it to the neighborhood near the Houjouya Festival, where he, Banba, and Lin find her phone and the transmitter on the ground. Enokida slips one into Martínez's pocket in volume six out of curiosity about his relationship with Ricardo Seiya Ortega. He passes along information he overhears about the Noma Group to Lin, who has been hired by a rival organization, and calls Lin for help when Martínez is captured by members of Los Eses. Knowing he has been bugged and help is on the way, Martínez provokes the Los Eses members to stall for time and works with Banba, Lin, and Ricardo to take down the Mexican cartel.

### Phone strap

The **redback spider phone strap** (セアカゴケグモ携帯ストラップ, *seakagokegumo keitai strap*) is first seen in volume 2, eighth inning, and episode five. It is the redback spider listening device version 2.0 attached to a simple phone strap. In both the light novel and anime, a drunk Banba shows off Enokida's new invention and tries to give it to Lin, who refuses it. When Banba attempts but is unable to put it on his own phone due to his intoxication, Lin grows irritated with his helplessness and does it for him. Lin later has Enokida track Banba's location to the Kakyuu Group's torture room, where he arrives in time to save him from one final would-be killer.

### Keychain

The **redback spider keychain** (セアカゴケグモ型キーホルダー, *seakagokegumo-gata keyholder*) is first mentioned in volume three, fourth inning. Lin runs into Enokida in JR Hakata City, where the informant is shopping for materials needed to make his new inventions. He promises to give some to Lin when he finishes. He later offers one to Genzo, but the mediator declines.

### Telecommunicator

The **redback spider telecommunicator** is first seen in volume three, seventh inning, and episode ten, where it is referred to as the "redback spider transmitter." Its purpose is to facilitate two-way communication between multiple devices. When Enokida has successfully made two devices, he gives one to Genzo so that he, reprising his former infamous hitman identity, can contact Banba and orchestrate his and Lin's escape. In the anime, Yamato is forced to wear one while pickpocketing for the informant.

### Bomb

The **redback spider plastic bomb** (セアカゴケグモ型プラスチック爆弾, *seakagokegumo-gata plastic bakudan*) is first mentioned in volume three, fourth inning, when Enokida tells Lin he is working on making a few new inventions. Genzo uses the explosives to break Banba and Lin out of the Kakyuu Group's execution room. Through contact with Genzo via the telecommunicator, Banba and Lin are ready to run when the wall of the execution room explodes.

### Hand grenade

The **redback spider hand grenade** (セアカゴケグモ型手榴弾, *seakagokegumo-gata shuryudan*) is first mentioned in volume three, fourth inning. Enokida is shopping for materials to make it when he runs into Lin. The informant later gives one to Genzo, who uses it against several Kakyuu Group members while covering Banba and Lin's escape from the organization's headquarters.