Osomatsu-kun's five brothers Karamatsu, Choromatsu, Ichimatsu, Jyushimatsu, and Todomatsu have been kidnapped by rivals Iyami and Chibita. Armed with only his slingshot and pachinko balls, Osomatsu-kun sets out to rescue his brothers.
Full Japanese

Osomatsu-kun Hachamecha Gekijou was originally developed for a 4-Megabit cartridge, but due to chip shortages being experienced by Japan, the game was notably reduced to a 2-Megabit cartridge. To accommodate this, Sega R&D 2 removed the second half of the game entirely, from the levels to the end-game credits.[5]

Fujio Akatsuka, author of the original manga, was outspokenly critical about video games and considered them to be a problem plaguing Japanese youth. After the release of Osomatsu-kun Hachamecha Gekijou, the author was so offended by its poor quality that during a meeting with Sega R&D 2, Akatsuka became enraged and threw an ashtray at one of the developers. Confirmed by multiple employees of both Sega and SIMS (which many Osomatsu-kun staff later migrated to), the story of Akatsuka's thrown ashtray spread to other employees within the company, and eventually to the gaming public.[5]

Played by: KAGE-008