Bullied by entire class and blackmailed by the class pres on day 1
It's fucking hilarious in retrospect how apt the comparison to Issei is.
Unironically he ended up so fucked up from being in an emotional relationship with that fallen angel and then getting killed by her, my man ended up with a trauma that ends up being resolved like 13-14 volumes in (read the LN, I like(d?) Highschool DxD too much) and that gets explored often but briefly for quite a while until they dedicate like 2 whole volume's B and part of the A plot to resolving it so he could actually get into a serious relationship with Rias, and from there actually decide to seriously pursuit romance with each of the other girls. It was amazing.
Here we don't have the same quality of dedication to exploring our MC's psyche, unfortunately, but he definitely shares the trauma from that (the equivalent being Takae's ploy) and like, 3-4 different instances of misunderstandings both crafted and coincidental that tensed him up something fierce and left him as he is RN.