Kiriha is starting to realize her feelings. Is it because how mature he is, how she can relax with him and talk honestly even about the bad parts of her that are very needy. It could also be that game devs set the women to be in love with him but in real life, they don't understand what made them fall for him. My other theory is since he has played the game multiple times, he gives off a stronger game lead presence then the original game lead.

はああ、脳が溶けるぅ。桐葉が俊樹と哲彦のどっちが好きなのか本気で悩んでるところが読んでて楽しすぎる！
続きが楽しみです！もちろん星押させていただきます。