Simple yet Sexy
A Hentai and Workplace series worth adding to your list.
Coworkers often gossip during breaks or go drinking after work hours. Ryouhei Hachiya and his Department Head are no different. But this time, in exchange for keeping the fact that Ryouhei skipped a day of work a secret, his Department Head dares him to invite the shy and disheveled office clerk Rena Yukuhashi out for a drink. He has a difficult time completing this menial task, since the Department Head's only goal is to find out if Rena is a virgin, but he does so anyway. On their outing, Ryouhei is unexpectedly mesmerized by Rena's appearance. Not only does she look stunning, but the way she speaks unrestrictedly pleases him. Ryouhei finds himself captivated by the previously reserved girl, and after their first night, their encounters become more frequent. However, complications arise when Ryouhei later tries to act cool around his Department Head.
Plot summary from MyAnimeList. Data and images via Jikan API.