Mizuno Shinobu no Risou no Renai: Otsukiai-hen

Mizuno, a thirty-something office worker who struggles with real-life romance and is a big fan of shoujo manga, ends up spending a night with his subordinate and crush, Meguro, under the influence of alcohol. While tormented by regret, Meguro casually suggests that they start dating...!? (Source: Shinshokan, translated)