Oh this is a fun question! Juni’s sexual preferences origins are something i haven’t explored in art yet! Hes got a weird relationship dynamic with his mother that kind of lead to him craving directness and servitude. When it comes to degradation, he’s really prone to getting embarrassed and crying easily so it became natural for him to sexualize that. He definitely read a lot of erotic doujinshi throughout puberty that influenced his more extreme tastes, especially ryona and hypnosis/mind control. Then being surrounded by friends like Makoto and Yamagishi he quickly started exploring sexually and playing out some of his kinkier fantasies.