Core Magazine Co. Ltd. (株式会社コアマガジン) is a Japanese publishing company focused on adult material, such as adult magazines and hentai. The company is the publisher of the Bible Black Visual Art Works book.
The company was established in 1985 as Shōnen Shuppansha (株式会社少年出版社). As of 2009, it is among top 5 ero-manga publishers in Japan.
In the July 2013, three staff members from Core Magazine were arrested and accused of selling magazines and manga that had sexual content that was insufficiently censored, a violation of Japanese law. As a result of the arrest, many publishers in Japan have increased their self-censorship to avoid obscenity charges.
Core Magazine official site (Japanese)