Yeah, but he is a teenager who really likes Hina so he doesn't want to seem uncool in front of her. He is also unaware of how Hina views him, so he thinks he has to impress her currently because he doesn't think she has an interest in him in that way.
You wouldn't want to show the person you like your uncool sides too soon because it may turn them off. We as readers know that won't happen, and in fact she would totally embrace the uncool side of him and find a way to think it was cool, but he is totally unaware.