Manjyudo Co., Ltd. (株式会社漫充堂) was a company that sold/exported amusement machines as well as operated leisure facilites and restaurants. It was established in March 1987. Eiko Iida (飯田英子) was the president. 
Research Methods: Actual mentions, shared staff
- Bouken Danshaku Don: The Lost Sunheart (JP Publisher: I'Max)
- Music Driver: Tomcat System?
As Big Club/Nihon Soft Hanbai?
Given her role as a producer on these games, Iida appears to have also run a company called Big Club (株式会社ビッグ・クラブ). Big Club apparently later became Nihon Soft Hanbai (日本ソフト販売).  There is no conclusive evidence that Big Club/Nihon Soft Hanbai became Manjuydo. Bouken Danshaku Don shares a lot of staff with the games below, but it is said Big Club/Nihon Soft Hanbai went bankrupt.
(In an interview Takane Ohkubo said, "The Genpei Pro group was dissolved after Bravoman, and I left Namco. I went to work at a company called Big Club, where I worked on Jinmu Denshou, Rock-On, and Bouken Danshaku Don for the PC Engine." )
- Armed F (JP Publisher: Pack-In-Video)
- Has a "Big Don" copyright
- Blade Land (unreleased) (Nihon Soft Hanbai) 
- Jinmu Denshou (JP Publisher: Big Club)
- Planning, Some Music: Wolf Team; Some Music: Goblin Sound
- Rock-On (JP Publisher: Big Club)
- Official website (Internet Archive Wayback Machine) (Japanese and English)
- Older website (Internet Archive Wayback Machine) (Japanese and English)