so i guess two of the biggest questions asked are "how did aoki get over hasshi so fast?" and "why is aoki liking ida so different from the way he liked hasshi?" 

imo, aoki's feelings for hasshi were shallow. like puppy love and infatuation. he had a version of her in his head i guess. he sort of idolized her more than actually liked her. 

so the reason why aoki's feelings for ida seem so different is because aoki is spending time with ida. he doesn't have  a set idea of what ida is already like in his head. he's getting to know ida and hes falling in love as he gets to know ida more. 

how aoki got over hasshi so fast? well, i kinda forgot my reasoning. someone made a topic on it (it got deleted tho) and i got it all out then so i haven't thought about it since lol. eh ok let me do some deep brain diving. personally, im like aoki. my crushes are shallow but if i start getting to know them, things get deeper. the deeper they got, the harder it was to let go. ive literally had crushes on people for a week and then never again. but i still think about the girl i liked 3 years ago wondering if she ever really liked me too (...that is a problem but nevermind that lol)

see its not really love. just "wow this person is really nice and pretty, i like them!" its not "i wonder how they are, i wonder if they like me, do they think about me too?". thats how aoki is. the way he describes his feelings for hasshi are more like the former. the way he describes his feelings for ida are more like the latter. see the difference? 

its why it hurt him so much when he couldn't tell if ida liked him vs when he found out hasshi didnt like him. sure he shed a few tears but how fast he got over it said everything. plus it was lowkey looking like he was frustrated with himself from how he couldn't confess more than actually heart broken over hasshi. whereas with ida, it was a lot of moping and pining after him. 

i kind of combined answered the questions oops. well, i hope this explains some stuff. you may have different opinions or more things to add so let me know bc i love discussing them so much lmao.

also. aoki losing feelings for hasshi so fast does not take away from the fact he is still bisexual. aoki is actually good bi rep and i say that as someone who is bi so yeah. they never forget aoki liked hasshi either. the secen of ida getting jealous was a cute scene (one of my fav scenes i hit replay so many times) but it also serves as a reminder aoki DID like hasshi (even if it wasn't deep, the feelings were still real) and he IS bisexual. 

btw just my opinions and assumptions. i based a lot of this stuff from my experinces and how my feelings work and i know not everyone experiences things the same way but i still wanted to just put this out there to help people understand a bit i guess. 

thank you for coming to my explanation (turned mini rant about how aoki is bi) ted talk lol.