I definitely want to second the first anon, you're doing a really fantastic job and honestly it really shows that you're consistently getting more and more comfortable with him the more you play, which is so great! I love that you put so much thought into keeping his tags interesting even though he's so shy, without actually sacrificing characterization for it. That's something that can be super hard for a lot of people, so seriously, props for taking the care that you do with that.
Another thing I really like (and you can totally correct me if I'm wrong in reading it this way) is the balance between his attempts at being polite around people in Kiseki versus how he actually kind of fails socially. You can tell how he tries to use proper terms with people but actually seems unsure of himself just a bit and I really like that. It seems very similar to how he behaves in canon, so whether it's intentional or not, your portrayal of him comes across really natural.
TL;DR you're doing great and I'm looking forward to seeing him more and more in the game.