Title: Ball Up (often stylized as B・ll Up)

Circle: グループ601 (Group 601)

Publisher: 沖由 佳雄 (Okuyoshi Yoshio)

Date of Issue: August 16, 1992 (exactly during Comiket 42, which ran Aug 14–16, 1992)

Printer: 集成社 (Shuusei-sha)

Pages: 90.

The book is effectively a fan-produced love letter to Otama, with the afterword directly stating:
“This book is a love letter to Otama and to Ms. Korogi Satomi [Otama’s voice actress].”

The editor acknowledges that Otama was a universally beloved character within the community and that multiple contributors wanted to celebrate her.

Contributors also mention they wished to feature other characters like Pururun, but ultimately it became Otama-focused.

Based on layout and tone, this doujinshi mixes illustrations, short comics, and character tributes rather than being a single long manga.