Research on "sperm flagellum activity" started by girls in the school's biology department. A school ejaculation monitor recruited to provide the male sperm necessary for the experiment. I was interested in how to provide it, so I went to the club room to ask... I was immediately hired and started collecting on the spot! At first, it was about using a masturbator to support ejaculation, but in order to collect the necessary amount of sperm for the experiment, the act escalated steadily... Kintama massage, cryptic play, masturbation so that sperm can be made into a lot of balls. I didn't think science girls such as show off and cosplay intercrural sex were such perverted girls! !