Ichijinsha

is a Japanese publishing company focused on manga-related publication, including magazines and books. As of October 2016, Ichijinsha was acquired by Kodansha and became its wholly owned subsidiary.

The company was first established in August 1992 as a limited company under the name Studio DNA whose main purpose was to edit shōnen manga. In January 1998, Studio DNA became a public company and moved from merely editing to now being a publishing company. In December 2001, a publishing company was formed named Issaisha which started the shōjo manga magazine Monthly Comic Zero Sum. In March 2005, Studio DNA and Issaisha merged into the current Ichijinsha company.

On April 6, 2023, it announced it was launching a new web manga brand Echo with e-book distribution service Comic Seymour. The brand will produce works targeted towards 20-40-year-old women (josei?).

Magazine

 * Febri (formerly Chara☆Mel)
 * Monthly Comic Rex
 * Monthly Comic Zero Sum
 * Comic Yuri Hime
 * Manga 4-Koma Palette
 * The four-panel comic strip magazine Manga 4-Koma Palette (まんが4コマぱれっと, Manga Yonkoma Paretto) started as a special edition of Comic Rex.
 * gateau
 * THE IDOLM@STER MILLION LIVE! MAGAZINE Plus+, renewal of THE IDOLM@STER MILLION LIVE! MAGAZINE

Web magazines

 * Zero Sum Online
 * comic POOL (jointly with Pixiv)
 * Curihime@Pixiv
 * Echo (launched 2023)
 * LOVEBITES (jointly with Seymour)
 * Manga 4-koma Palette Online

Defunct magazines

 * Comic Yuri Hime S
 * Waai!
 * Waai! Mahalo
 * Comic Zeru-Sum Zoukan WARD
 * Manga Palette Lite
 * Niconico Yuri Hime (web magazine, jointly with Nico Nico Douga)

Anime production

 * Wotakoi: Love is Hard for Otaku
 * Masamune-kun no Revenge
 * Citrus
 * Mikakunin de Shinkōkei
 * My Next Life as a Villainess: All Routes Lead to Doom!
 * Karneval
 * Shomin Sample
 * Koi to Yobu ni wa Kimochi Warui
 * Watashi ni Tenshi ga Maiorita!
 * Hitorijime My Hero