The scene with him and Izumi was really interesting especially for what it was unintentionally showing; if you're genuine and honest and can be confident even in things that others especially find it difficult to do, no matter if they're a "popular" thing or not considered trendy by all, you'll naturally attract people to you. Confidence and how you display yourself are so important when it comes to interacting with people because even if they're not into the same stuff you are they can sense how genuine you are and that's a really attractive thing whether you're into them as a friend or more.
It's also nice how he notices that things are going well and doesn't trust himself so she has to tell him that he was responsible for all that because when you don't have self-confidence you attribute your accomplishments to luck or fate or circumstances outside your control when in reality it's your own hard work.
Meanwhile, like many dudes, this guy doesn't wanna commit to her but doesn't like it when she starts paying attention to someone else so maybe you should just be honest and not a dumb-ass.