Remind me again - how old is Kagari supposed to be in the series?
Close to 20 or below 18? I don’t remember if she’s getting close to graduating high school or not. If she’s close to 20 then it’s Nana being over-cautious. If she’s below 18 that’s a no-fly zone, Samurai. Japanese statutory laws are somewhat hazy (technically increased from 13 to 16 in 2023 but most prefectures have laws pretty much making it effectively 18) - a young salaryman getting his freak on with a high school student and being busted will likely get you into fairly deep doo-doo with your employer, who takes a fairly dim view with their names being associated.
Either way, my guy Nana-kun probably has to douse his balls in liquid nitrogen nightly to cool down from those assaults, because YEEEEEEEESH the amount of self-restraint exhibited here is on a completely new level.