Suzu's self-crowned nemesis. Used to be in a pop-group with Suzu until Suzu quit, leaving Jun stranded in Tokyo after moving there from Osaka. She now seeks revenge for that on Suzu.

Katsu Kaizou is a very gullible, 17-year-old high school student and a believer in science fiction, aliens, ghosts, UFOs, conspiracies, etc. He thinks that everything going on around him is the result of some sort of alien plot to take over the world. Each story is pretty much self-contained and is completely bizarre. Kaizou joins the school's science club, makes new friends, and ends up coming in contact with all sorts of strange things like log people, deadly sushi, pee-blades, scary infections, robot invasions, ghosts, living dolls, and more!

Katsu Kaizou is a very gullible 17 year old high school student, and a believer in science fiction, aliens, ghosts, UFOs, conspiracies, etc. He thinks that everything going on around him is the result of some sort of alien plot to take over the world. Each story is pretty much self-contained and is completely bizarre. Kaizou joins the school's science club, makes new friends, and ends up coming in contact with all sorts of strange things like log people, deadly sushi, pee-blades, scary infections, robot invasions, ghosts, living dolls, and more!
 
Included one-shot: 
Volume 13: Yuuryou Bukken Chuukai Shimasu