Katteni Kaizō (かってに改蔵) is a Japanese manga series written and illustrated by Kōji Kumeta. It was serialized in Shogakukan's Weekly Shōnen Sunday from May 1998 to August 2004, with its chapters collected in 26 tankōbon volumes. An original video animation (OVA) series adaptation produced by Shaft was released from May to October 2011.

Plot

The series follows the strange goings-on that surround Kaizō Katsu, an eccentric student who has a unique perspective on the world around him. He was once a child prodigy but at the age of 7, his childhood friend Umi Natori kicked him off the jungle gym and he suffered a head trauma, changing his personality. He gained a huge interest in various weird things such as UFOs and ghosts. At 17, Kaizō was hit by a human anatomy model that accidentally dropped from the second floor of the school building. Being revived with a defibrillator, he starts to believe he was rebuilt as a cyborg by the president of the science club, Suzu Saien, who facilitates that belief for her own entertainment. Kaizō joins the science club and becomes a constant annoyance to Umi and also the bane of the existence of another member of the club, Chitan Tsubouchi. At the time of his accident at the age of 7, Kaizō was also attending the Genius Cram School, a local institute for prodigies in various fields like sleeping or fashion. However, after the accident a dazed Kaizō destroyed the building by inadvertently mixing dangerous chemicals. Now the science club constantly runs into people that also used to attend that same cram school and display even more eccentric behavior than Kaizō himself.

Characters

Media

Manga

Katteni Kaizō is written and illustrated by Kōji Kumeta. It was serialized in Shogakukan's Weekly Shōnen Sunday from May 6, 1998, to August 4, 2004. Shogakukan collected its chapters in twenty-six tankōbon volumes, released from January 18, 1999, to September 17, 2004. In 2010, Shogakukan started re-releasing the manga in a 14-volume shinsōban edition, to celebrate Kumeta's 20th anniversary as a manga creator. The volumes were published from April 16, 2010, to June 17, 2011.

Volumes

Original video animation

In January 2011, an original video animation (OVA) adaptation of the series was announced. Three volumes, each one including two episodes, were released from May 25 to October 26, 2011. The series was directed by Naoyuki Tatsuwa under the chief direction of Akiyuki Shinbo at Shaft. The series was written by Katsuhiko Takayama and Shaft, features character designs from Hiroki Yamamura (at the time from Studio Pastoral), and has music by Ruka Kawada. The episodes are split into segments, and some episode's segments were outsourced to other studios: episode 2 and 6's B-parts were outsourced to Studio Pastoral, and episode 5's A and B-parts were outsourced to Asahi Production. Yamamura also served as chief animation director across the series, and Yuka Kudou also acted as chief animation director for episode 5's A and B parts.

Episodes