What if Mihashi were at Seido? The era of ace pitchers is ten years later than that of Diamond no Ace, and the ball speeds are different too. So I've increased Mihashi's pitching speed in this story to 120 and also improved his control a bit.
Just to explain, the Mihashi I have in mind isn't the kind of boy who would easily give up baseball. Even after being treated so badly at Mihoshi, he still stood on the pitcher's mound and kept going. He definitely has the determination of an ace who never gives up. What Mihashi needs most is a partner. As long as he has his partner's support, he can become confident. Maybe that's not how you see him, and he might be OOC.
I personally think that in Seido's cheerful environment, Mihashi might not be quite so introverted.
Sorry, I ran into some problems and feel like I've gotten Mihashi's character a little wrong. I need to revise it, so I'm putting this on hold for now. I'll work on fleshing out his character first.