Orange Club: Maruhi Kagai Jugyou

Orange Club: Maru-hi Kagai Jugyou (Japanese: オレンジクラブ ㊙課外授業, translating to "Secret Extracurricular Lesson") is a highly obscure, adult-oriented strip mahjong arcade game released in Japan in February 1988. It was developed and published by Daiichi Denshi (with historical associations to Nichibutsu's hardware and sub-licensing framework).

The game functions as a standard 1-on-1 Japanese Riichi Mahjong match against the CPU.