My Youth Romantic Comedy Is Wrong, as I Expected @ Comic, Vol. 22 (Manga) - Wataru Watari

A sudden accident first brought together Hachiman Hikigaya, Yukino Yukinoshita, and Yui Yuigahama. Then they became the Service Club, helping others with their woes while working through their own complicated emotions. As the club now fulfills one last job--throwing the best interschool prom they can--the trio must think about how their relationship has changed and what future lies ahead for them. Their youth romantic comedy, mistakes and deviations and all, concludes here!