At a drinking party, the mean senpai asks Iida to date him. Somehow he agrees, but this relationship turns out to be everything else than lovey-dovey!! Treating him harsh at work and in private!! Then something happens that makes Iida snap!! How will senpai react to Iida avoiding him?!
(Source: Tokyo Mangasha, translated)
Included one-shot: Umaku Ikanai Shitsuke no Houhou