This protagonist needs to man-up ASAP. There's a prime, A-class waifu confessing to him right now.
If this this guy doesn't kiss her, after her opening her hearth like that, then man I'm so disappointed.
Gotta wonder if this guy lost his confidence/self-esteem to that isekai-world,
since he's still so insecure, despite being probably the one of the strongest beings walking this (manga's) earth..