나마이키 ~생수장에 어서오세요!~ The Animation

Ashifuji Satoshi is hired as the caretaker of Kissuisou dormitory, which is home to three female occupants: cheerful coach Esumi Mei, surly guard Ogata Saki, and perverted mangaka Umi Rurika. However, almost immediately after landing the job, Satoshi is contacted by Ibaraki, the house spirit of Kissuisou. Ibaraki's power is drawn from seeing people copulate. Thus in order to restore her strength, the spirit orders Satoshi to offer his sperm to each woman in the house and Satoshi begins this peculiar task with her assistance.