It's not strange that he thinks insecure like that, isn't it? He thinks that she is with him because of the size of the Cosplay, you as a reader know what Marin thinks, but if the only thing that unites them is the Cosplay, it is logical that he thinks that if it is successful he will leave it aside, I see a criticism very one-sided only for the male character who compared to others this is one of the best to the point of seeing his development in the subject of clothing, elaboration and also makeup among other things, that is what the series is about, he does his job and goes improving, her cosplay but in terms of changed personality, even if it is a little, the protagonist is ahead of her...