A Certain Item of Dark Side

A Certain Item of Dark Side (Japanese: とある暗部の少女共棲（アイテム）, Hepburn: Toaru Anbu no Aitemu)^[a] is a Japanese light novel series written by Kazuma Kamachi and illustrated by Nilitsu, which is a spin-off of Kamachi's A Certain Magical Index series, focusing on the women belonging to Academy City's dark side. ASCII Media Works have published four volumes since March 2023 under their Dengeki Bunko imprint. A manga adaptation with art by strelka has been serialized in ASCII Media Works' shōnen manga magazine Dengeki Daioh since October 2023 and has been collected in two tankōbon volumes. An anime television series adaptation has been announced.

A Certain Item of Dark Side
First light novel volume cover, featuring Frenda Seivelun and Shizuri Mugino
とある暗部の少女共棲（アイテム） (Toaru Anbu no Aitemu)
Genre	Action Science fiction
Light novel
Written by	Kazuma Kamachi
Illustrated by	Nilitsu
Published by	ASCII Media Works
Imprint	Dengeki Bunko
Original run	March 10, 2023 – present
Volumes	4
Manga
Written by	Kazuma Kamachi
Illustrated by	strelka
Published by	ASCII Media Works
Imprint	Dengeki Comics NEXT
Magazine	Dengeki Daioh
Original run	October 27, 2023 – present
Volumes	2
Anime television series

Characters

See also: List of A Certain Item of Dark Side characters

Shizuri Mugino (麦野沈利, Mugino Shizuri)

Voiced by: Ami Koshimizu^[1]

Rikou Takitsubo (滝壺理后, Takitsubo Rikō)

Voiced by: Aya Suzaki^[1]

Frenda Seivelun (フレンダ セイヴェルン, Furenda Seivuerun)

Voiced by: Maaya Uchida^[1]

Saiai Kinuhata (絹旗最愛, Kinuhata Saiai)

Voiced by: Chinatsu Akasaki^[1]

Chōbi Hanano (華野超美, Hanano Chōbi)

Media

Light novels

Written by Kazuma Kamachi and illustrated by Nilitsu, A Certain Item of Dark Side began publication under ASCII Media Works' Dengeki Bunko light novel imprint on March 10, 2023.^[2] Four volumes have been released as of March 7, 2025.^[3]

No.	Release date	ISBN
1	March 10, 2023[4]	978-4-04-914939-5
Prologue: Feminine, Dangerous, Bright (序章 フェミニンデンジャラスブライト) Chapter 1: The Fifth Girl (第一章『五』人目の少女) Chapter 2: >>Colosseum. (第二章 >>Colosseum.) Chapter 3: A Certain Courage, A Secret Reward (第三章 とある勇気、秘密の報酬) Chapter 4: Level 5 Roars (第四章 超能力者は咆哮する) Epilogue: A Road That Leads to Somewhere Someday (終章 いつかどこかに繋がる道)
2	August 10, 2023[5]	978-4-04-915081-0
3	June 7, 2024[6]	978-4-04-915699-7
4	March 7, 2025[3]	978-4-04-916233-2
5	September 10, 2025[7]	978-4-04-916593-7

Manga

A manga adaptation illustrated by strelka began serialization in ASCII Media Works' shōnen manga magazine Dengeki Daioh on October 27, 2023.^[8] The manga's chapters have been compiled into two tankōbon volumes as of April 2025.^[9]

No.	Release date	ISBN
1	June 26, 2024[10]	978-4-04-915751-2
2	April 24, 2025[9]	978-4-04-916381-0

Anime

An anime television series adaptation was announced during the "Dengeki Bunko Winter Festival 2025" livestream event on February 16, 2025.^[1]

Notes

1. The kanji 少女共棲 in the Japanese title is read as Shōjo Kyōsei.