Gekkou-zaka no Hanayashiki  

月光坂の花屋敷, Gekkouzaka no Hanayashiki

Yukiya Kashiwagi and his son Yuuto reside in a mansion that was inherited from their grandparents. The mansion is surrounded by flowering trees and also houses Takanashi, who used to be a student there but now stays because it's convenient for him to work. However, Takanashi has developed feelings for Yukiya-san and is determined to uncover the secrets that he holds.