I think so, because he literally follows Asahina around, goes up to her all the time with nothing to say, and always just try to get close to her even though she obviously hates him from the outside (since from Asahina's actions, it's obviously that she hates him)...
Just think, if you got a guy that comes close to you every day, tries to talk to you without any particular topics, boasts about his achievements, follows you to just about everywhere and stares at you about 24/7, how would you feel :P
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I mean, by episode 7, it's pretty obvious that Yamato is becoming a stalker rather than having a crush (although it's not LITERALLY true, but by his actions, it seems so...) Yet, it's not until 25 that he realizes that he's done for -_-