Shokuinshitsu no HimegotoShokuinshitsu no Tsumujikaze; 教職員室的祕密情事; 職員室の秘めごと; A Secret of Teachers' Room

Nishio, a stoic math teacher, doesn't get along very well with Sakaki, the beloved gym teacher. However, after one drunken night, Nishio finds himself in Sakaki's bed where he is suddenly kissed and confessed to...?