Hibiki Amamiya works for a company as a volleyball player. I often have to work overtime due to computer work that I am not used to...and suddenly it rains! Amemiya, who is left behind at the company with his girlfriend's senior employee, reluctantly decides to let her senior employee stay at her home. ``Senpai, you're being rational, aren't you?'' I know it's not good, but my co-worker's unprotected firm breasts drive the man crazy. "You can't do that, right? My wife will get mad at me...Ah, it feels so good..." The man can't stand the wet, sharply curved big tits of the new office lady who is weak against pressure, so he puts his wife aside and licks and inseminates her! !