He's simply shy. Also I tried to make it semi-realistic, because he wasn't just a brother but basically like a caretaker/father figure for his sister too and she's basically sacred for him. No one would just accept that kind of relationship from the get go (unless you are super fucked in the head like me lol, but I prefer a slow burn story so that's what I made). And don't worry, there's character development so he opens up later.I'm sorry but i need to ask, I still haven't finished chapter 1, but is there a reason for Erik to be the way he is? I feel like it's a bit much. I don't know if it has been asked before, and I'm guessing he'll change a bit moving forward but still. I know there's like 90% of games here where the MC/Male Figure is way too overconfident, but I still feel like he's being a bit too annoying, in the way he's reacting to the whole situation. I know this might probably be an unpopular opinion...
I didn't want my VN to have the usual male chad thundercock who fucks everything that moves from the start. I think what I crafted instead with Lyna being the centerpiece of the story is much more exciting, erotic and perverted...