Toritsu Mizusho!.

都立水商!

The School of Water Business (都立水商!, Toritsu Mizusho!) is a manga series created by Shinobu Inokuma, the author of Salad Days. It is based on a novel by Hikaru Murozumi, and is set in a fictional trade-school-that focuses on the mizu shōbai-located in the Kabukichō district of Shinjuku, Tokyo. The school's focus is to give students their last chance in the school system.