My Youth Romantic Comedy Is Wrong, As I Expected @ comic, Vol. 20 (manga) — Wataru Watari

The fake prom scheme has run its course, so it's time to end the charade and relax a little with a karaoke party! But as the festivities wind down, Yui has a very personal request for Hachiman…one that has him thinking seriously about her. With the real Soubu High School prom on the horizon, what better setting is there for some classic teen drama?