Do you think Aomine and Kise were friends at Teikou? To me it's obvious that yes, they were. Of course, it wasn't exactly the same kind of friendship as Aomine had with Kuroko/Momoi, but still, all those little moments when they act like total dorks with each other (personally I can't remember seeing Aomine acting like that with Kuroko), or the fact that Aomine always go out of his way to bully Kise in that sweet way of his (though there's more of it in drama cds/novels than in actual manga)...
Ahh.. First thing first, this is all based on my own personal opinions, and in my point of view Aomine and Kise are indeed friends at Teikou AND canon-wise they are still friends even in the current arc.
I wouldn’t deny anything that Aomine has with Kuroko, or what he has with Momoi. In the first place, it’s easy to tell that Aomine and Kuroko were the best of friends back then in Teikou (at least before the awakening of douche!Mine) and I don’t even need to elaborate on why because they’re lucky enough to be provided with a lot of back-story about their relationship in the past, simply because Kuroko is the main character so of course the majority of the manga focused on his side of the story.
However, while they agree on basketball, they couldn’t agree on any other things, but even so that doesn’t stop them from being friends. And while I can actually see that Kuroko might be kind enough to follow Aomine doing other things that aren’t revolved around basketball, at the same time he might not be able to entertain Aomine’s way of thinking, not being able to share Aomine’s view because yeah they can’t agree on anything else aside from basketball. Even so, Kuroko is an observant person, so of course he understands Aomine a lot.
Those two aside, just like Anon-chan said, Aomine and Momoi are childhood friends so they most likely share a kind of unbreakable bonds between one another, almost the same just like how siblings are except that they’re not exactly siblings. Momoi is a sharp girl from the start, she is an expert in collecting data so it’s logical enough that she knows a lot about Aomine since they have been around each other for years.
When it comes to Aomine and Kise though, they first met each other in kind of an abrupt way. As far as we know, as in canon-wise, everything is purely on a coincidence, Aomine’s ball hits Kise’s head at the right time when the blond needs someone to light up a fire within him, and Kise takes his own step to enter the basketball club because he admires Aomine’s style of basketball.
While Kise admires Aominecchi more than anyone else, he DOESN’T blindly admire him. If you have listened to the Drama CD(s) and read enough of the manga + the novels (novels and Drama CDs are canon stuff too mmkay?), particularly on their times during Teikou arc, you can tell that Kise is not dumb. Despite him being an airhead and at times he might fall into Aominecchi’s pace when it comes to the dumbest of things like Aomine asking him to imitate Midorima to cover the fact that he had broken an exercise bike (and this is actually in high school), Kise knows what is right and what is wrong when it comes to a much more serious matter.
Before Kise joined the basketball club, he was alone, he could hear the sound of the wind blowing around him. And this is critical because Kise is someone who is always surrounded with people, people who admire his skill in being able to play any sport, people who love him for being a model. But that’s just that and Kise still felt lonely amidst the crowd around him.
When he entered the basketball club, we often see Aomine bullying Kise and them being a couple of dorks fighting with each other even in a petty stuffs. But that is a prove that they ARE friends. Like you wouldn’t feel comfortable enough to bully or tease someone if that person isn’t someone that is close to you. It’s only because the both of you are close, that you know there’s not much limitation in doing what you want and what makes you feel at ease because that is exactly what friends are for each other, they make you feel comfortable, they make you feel like home, like you belong to a place.
Kise needs a constant reminder that his place isn’t so high on the pedestal, ALONE, where most people see him for his talents, he needs a constant reminder that he belongs to a circle of people and Aomine knows how to push that simple thing into Kise’s slow mind.
Despite of that, Kise DOES NOT blindly follow Aomine around.
