Des：Yukina single-handedly raised her son Masaaki until he graduated from university, and successfully secured a job. Masaaki started living alone when he got a job, and Yukina ended up living alone and lonely. On the day of Yukinas 50th birthday, Masaaki invites her to go on a hot spring trip as a birthday present. On her trip, Yukina gets excited when she sees Masaakis body for the first time in a while. Masaaki also got an erection when he saw his mother in her underwear. Where will these two end up...