Star Seas Company | OpenBizGraph

§01

Basic information

BASIC

Head office: 4th Floor, Onwa YK Building, 1-17-14 Onwa, Bunkyo-ku, Tokyo 112-0013
Chief executive: Katsushi Ota
Capital: 10,000,000
Employees (non-consolidated)
Employees (consolidated)
Start date: 2010-04-28
End date

§02

Websites

1 DOMAINS

https://seikaisha.co.jp/

§03

Business

3

Publishing

Website planning and production

Event business

§04

Related companies

1 COMPANIES

Company name	Group	Parent	Subsidiary	Customer	Supplier	Alliance	Bank	Shareholder
Kodansha Co., Ltd. Shareholder

Names without a link are companies not yet registered in OpenBizGraph

§05

Network

NETWORK

§07

News

10 ARTICLES

2026-10-20

『The Night of the Wizard』 Book Reading Celebration

In commemoration of the release of the novel "The Night of the Wizard: The Downfall," a book reading event will be held on November 11, 2026, at the Important Cultural Property, Freedom Academy Asukakan (Ikebukuro, Tokyo). The event will run for three sessions, each with 50 participants. Attendees will receive copies of the book at the venue and enjoy a 30‑minute reading session accompanied by tea and cookies. Details and ticket purchases are available on the information page.

2026-10-19

"Happy Kanako's Hitman Life" TV Anime Adaptation Announced

The TV anime adaptation of "Happy Kanako's Hitman Life" has been announced. The original work is a four-panel manga by Minoru Wakamura, with total comic sales exceeding 1.2 million copies, and the live-action drama was also a huge hit. The anime is directed by Shinji Takamatsu, with Drive handling production.

2026-10-19

『幸せカナコの殺し屋生活』POP-UP STORE開催

若林稔弥さん原作の漫画『幸せカナコの殺し屋生活』のPOP-UP STOREが、渋谷サクラステージのTO POP-UPで開催されます。期間は2026年10月30日から11月9日まで、各日10時～21時です。ステッカー、クッション、ぬいぐるみ、アクリルスタンドなどのグッズが登場します。

2026-10-05

Novel 'The Night of the Wizard' Bonus Information

In commemoration of the publication of 'The Night of the Wizard', free and paid purchase bonuses are available at various bookstores. At Animate, clear files and A.B-T.C. items are offered; at Shosei Group, illustration cards, acrylic stands, and at Melonbooks, clear files and tapestries are provided. Please check each bookstore's announcements for details.

2026-09-24

"Happy Kanako's Hitman Life" Season 2 Streaming Begins

The live-action drama "Happy Kanako's Hitman Life" Season 2 began exclusive streaming on DMM TV from September 17, 2026. Following Season 1, Nono plays Kanako and Taisuke Fujigaya portrays Sakurai.

2026-09-24

TV Anime Adaptation of 'God's School Dropout' Announced

The TV anime adaptation of 'God's School Dropout', based on the novel by Natsu Hyuga and illustrated by Modomu Akagawara, has been announced. The original novels are currently available in volumes 1-5 from Seikaisha FICTIONS.

2026-09-14

Novel "Mage's Night" Volume 2 Release Date Change and Bookmark Color Update Notice

Star Sea Publishing FICTIONS announced that the release date for Volume 2 has been moved to Tuesday, November 10. This change was made because the positive reception of Volume 1 led to an increase in the first edition print run for Volumes 2 and 3, requiring additional time for printing and binding. Additionally, the color of the bookmark (bookmark string) will be slightly altered starting with the reprint edition.

2026-08-27

Special Site for the Novel "The Night of the Wizard" Released

The special site for the novel "The Night of the Wizard" (Star Sea Publishing FICTIONS) has been released. The site includes an introduction, character profiles, publication information, and messages from Kinoko Nasu and Hiromi Koyama. Additionally, details about the film adaptation, "The Night of the Wizard," scheduled for release on November 20, 2026, are also presented.

2026-07-28

Seikai Co. Booth Merchandise Announcement! Open 8/1-2

Seikai Co. will participate in the "Fate/Grand Order Fes. 2026 Caldeia Academy Festival ~11th Anniversary~" and will exhibit a booth in the Fate Project & TYPE-MOON AREA / Hall 4. The opening time is 9:00 a.m., and we will sell fan-shaped hand fans and metal bookmarks, which are cash-only, while supplies last. Please check the "Frontline" blog for details.

2026-07-23

"Let's Do Crafts with Milk Cartons!" Book Release Perfect for Summer Homework

The popular craft content "Let's Make with Milk Cartons!" from the official Seiyu Meg Milk website has been turned into a book for the first time and will be released on July 31. The book introduces 50 highly popular ideas in full color, categorized by level for elementary school lower, middle, upper grades, and adults. It is packed with craft ideas that can be used for summer homework, using everyday food waste such as milk cartons and other familiar items.

§08

Public records

GOV

National Tax Agency basic information8010001132478

Source: National Tax Agency Corporate Number Publication Site, basic three items

Trade name: 株式会社星海社
Trade name (kana): セイカイシャ
Name in English
Corporation type: 301
Address: 〒112-0013 東京都文京区音羽２丁目１２番２１号
Postal code: 1120013
Prefecture code: 13
City code: 105
Address outside Japan
Prefecture in English
City in English
Address outside Japan in English
Corporate number assignment date: 2015-10-05
Update date: 2019-03-04
Change date: 2015-10-05
Registry closure date
Reason for registry closure
Successor corporate number
Details of the change
Latest record: 1
Excluded from search: 0
Processing type: 01
Correction type: 1
Trade name image ID
Address image ID
Sequence number: 2318396

METI gBizINFO8010001132478

Source: gBizINFO (Ministry of Economy, Trade and Industry)

Corporate number: 8010001132478
Trade name: 株式会社星海社
Trade name (kana): セイカイシャ
Trade name (alphabet)
Registry closure date
Reason for registry closure
Registered address: 東京都文京区音羽２丁目１２番２１号
Postal code: 1120013
Prefecture: 東京都
Prefecture code: 13
City or district: 文京区
City code: 105
Street address: 音羽２丁目１２番２１号
Organisation type: 301
Processing type: 01
Correction type: 1
Status
Representative
Capital
Employees
Employees (male)
Employees (female)
Business summary
Website URL
Year founded
Business category
Date established
Unified government qualification - grade
Unified government qualification - business items
Update date: 2019-03-04
Key information: 8010001132478

§09

Sources & updates

SOURCES

SOURCEhttps://seikaisha.co.jp/about/company-profile/

NEWS ●https://seikaisha.co.jp/news/Collected

DOMAINOwn domain：Yes

UPDATED2026-11-11 15:56 · Model: gpt-oss-20b(99)