Please don't be sorry about long comment, because I absolutely LOVE reading them LMAOO. First of all, thank you for playing the game! I'm really happy that you enjoyed it! And the fact that you've read all my dev logs/notes? I really appreciate it!
And oh my god the very first version of Yuzuki's route? Okay, I hope you don't mind receiving a long comment from me either haha.
*Spoilers below*
So I'd imagine that Haruto just straight up doesn't exist in this AU. Yuzuki and Ichigo know each other since high school, but they only know each other's existence until Aimi starts to talk to Yuzuki. Afterwards, Aimi fell for his kindness and Ichigo being Ichigo, he would decide to investigate (...and by that I mean stalk) Yuzuki just to see if Yuzuki reciprocates or not.
If we're on the canon AU, this is where Ichigo would see him hanging out with Haruto and feel relieved to find out that they're lovers. However, since Haruto doesn't exist, Yuzuki is just all alone. Ichigo couldn't find out what the guy is thinking or if he has any crushes by just stalking him, so then Ichigo would start talking to him and trying to get close to him to gain information (and maybe try to hook him up with some other person that fits Yuzuki's type).
You mentioned it, and yes, those two have kind of a lot of stuff in common. How they're both only putting up a facade and all. Even though their friendship started as a way for Ichigo to get information, in this story, Ichigo and Yuzuki genuinely became pretty close friends. Ichigo started seeing Yuzuki in a better light, while Yuzuki started developing a crush on Ichigo (which is something Ichigo never expected lol).
And that's for the backstory, as for how the route would went, the story would start the same way (minus all the dead bird thing) until the route selection. In Yuzuki's route, Yuzuki would reject Aimi's confession, saying that he has a crush on someone else. Aimi wouldn't kill him out of rage, she only did so in the canon route because he's going to leave town. Since she'll still be able to see Yuzuki, she reluctantly accepts this fact, but then she'd also plan to find out who his crush is and try to ruin everything for them. Yuzuki would ask Aimi for a friendly date regardless and Aimi accepts.
During the valentine's day, they would hang out together (with Aimi occasionally trying to get Yuzuki to spill the beans) until the evening, where Yuzuki says that he has an important business to do and just leaves. Aimi follows him, and this is where we find out that his crush is Ichigo because he dips the MC to go confess to Ichigo (yes this pisses the hell out of Aimi as she feels betrayed and shocks Ichigo to his core LMAO). Ichigo rejected Yuzuki of course, but Aimi left before she could hear him reject Yuzuki because don't we all love miscommunications.
Aimi's anger then turned for the worse. The day after valentine's day, she storms into Ichigo's house and ended up killing him out of rage, right in his parent's room too, because lol the irony. I haven't really thought of how it would go afterwards, honestly. Feel free to come up with your own endings (or if you want to write your own spin to this route, that's absolutely fine too! I'd love to see how you write your take in this situation) if you decide to write the fic (and please send it to me too I want to read it, I'm curious LOL)
Once again, thank you for playing and thank you for the comment! I hope you don't mind reading all that LMAOO