...I wouldn't say that he's dense, but hesitant. And with good reason; it doesn't seem as if he's ever thought of her in that way prior to how she's acting now.
Not sure if this MC is really dense, it seems like he's noticed how she feels but every time he wants her to elaborate something prevents it from happening. I'll give it a few more chaps simply because akinosora's art style is top tier.
To be fair, MC isn't being dense. He tries to talk to her about it but she interjects something and abruptly leaves. He figures it out, but she's baiting him along so he has more of a reason to keep coming back.
I understand you MC-kun. Its unbelievable that a beautiful girl just comes to you and suddenly starts giving you attention. You think you know the truth but just can't accept it. Most of the relationships are like that. And it really has a beautiful art style.