renji is a young child in the flashback and he's repeating a lot of standard "men like x women like y" gender role stuff because this is what he's been exposed to. i don't think it's unusual for children to uncritically parrot things like this they might have heard parents or teachers say + the rest of the story is about an adult renji thinking "hmm maybe those things i believed to be unshakable truths as a young boy were inaccurate."
ofc i understand if reading these sentiments is uncomfortable or upsetting, so please don't force yourself to read the story if you don't want to. you should prioritise yourself!
ebi hime do not listen to this person please please please write more trans men bl. i am a big fan i dont use this acc oftem anymore but i am certified fan i have the blackberry honey physical edition listen we real fans need this. ii would draw every sprite and cg in a million word tboy bl vn if u wrote one for free i love ur writing that much please do not fall to this evil