Latest piece by @FULLHERO@baraag.net. Thanks again!
Shizuka's research goes beyond just boy's anatomy. There's also sexual behavior, both in the giving and receiving positions. If you're asking why she doesn't have sex with the boys herself, 1) SOMEONE needs to be recording and getting every important angle, and 2) she has very low stamina and tends to pass out quickly when experiencing too much stimulation (more on that later).