HAPPY☆LESSON: THE FINAL

When Mitsuki learns that the highschool is going to destroy the old school building, she is saddened at the thought of so many memories being erased. Chitose and the rest of the moms spring into action to stop the demolition. During their efforts, Fumitsuki, Chitose, and Mitsuki finally realize their true feelings. (Source: Anime News Network) — Description from AniList community (anilist.co).