Highschool students Katsuyuki and Haru suddenly become brothers when Katsyuki's mom marries Haru's dad. Katsuyuki tries to manage his crush on Kyoko-chan while also solving mysteries at their highschool with Haru.

Title: あぶない放課後
Title (romaji): Abunai Hokago
Also known as: Dangerous After School
Genre: Comedy
Episodes: 11
Broadcast network: TV Asahi
Broadcast period: 1999-Apr-12 to 1999-Jun-21
Theme song: "Believe Your Smile" by V6

Ninomiya Kazunari
Shibutani Subaru
Kato Ai
Mizukawa Asami
Yamaguchi Morihiro
Iwaki Koichi
Takagi Saya
Takahashi Katsumi
Kato Reiko
Nishio Mari
Nakazawa Junko
Inoue Takashi
Matsuda Naoki (松田直樹)
Tamaki Hiroshi

Screenwriter: Noyori Miyuki (野依美幸)
Producer: Kuwata Kiyoshi, Fuse Hitoshi
Director: Sugiyama Noboru (杉山登), Ichino Ryuichi, Muguruma Shunji
Music: Morita Kazuyuki (森田和幸), Shiraishi Satori (白石紗澄李)