Ahhh, this is a really good essay!!
There's a really good scene of Minamisawa that's in (currently untranslated) a drama CD that takes place between Holy Road and Chrono Stone, where Minamisawa got agitated over Gouenji and Kidou calling Sangoku's version of Rairaiken's rice bowl "not real Rairaidon" and went on an argument with Kidou over it loolll. I love how he went from apathetic to openly defending his friends...
(yes Gouenji and Kidou picked fights with middle schoolers. And Kidou got offended over Minamisawa calling him old. Grown ass adults)
I love Minamisawa's arc, I'm sad he left Raimon so early on bc I would've loved to see more of him, but it's still so satisfying.
I really like that he and the rest of Gassan Kunimitsu had to learn that they can't always depend on Fifth's rules. the team had already been following them even before Minamisawa joined, and he was already okay with - and kind of hoping - to just be able to fall in line and graduate with a good-looking student record. but having been in Raimon before, that seed was already planted about fighting for what you love, and he realized just what it was that he truly wanted- and that the only way for him to get it, was to fight like hell for it.
and I love that his teammates saw him give it his all and realized that Fifth's rules had been holding them back, and then and there decided to abandon those rules and throw themselves into the battle. not just to win, but for Minamisawa. because he fought so hard, against his old team no less, for something they were all hoping would just fall into their lap if they behaved and did as told. he, a newcomer, proved to them that standing by and watching wouldn't help them, and instead of disregarding him, they accepted his influence and fully committed to playing a fair and fun match. in a way, Minamisawa was to them what Tenma was to Raimon- a revolutionary wind.
him playing against his old team in the first place brings a lot of good drama also, like the betrayal and the anger and confusion- I don't know just how close he was with the other third years, but I think one of them mentioned that he hadn't told them anything about what school he was transferring to, or even that he was transferring at all. to their knowledge he just quit the soccer club and that was it. any feelings of betrayal make sense, this came out of nowhere for them.
and on his end, there seems to be some frustration about how things unfolded- he didn't leave for no reason after all, and even though he jumped at the opportunity to, it doesn't mean he feels apathetic about it. Minamisawa seems like the type of guy to act cool on the outside, but ruminate on things quite a lot inside his head. and he's not emotionless, leaving the team and Raimon as a whole had to be a big step for him, I just believe that he chose not to show it. it would be easier for everyone that way.
I really love that he acknowledged Tenma as a good player and a worthy addition to Raimon, giving credit for stirring the team with the wind of revolution. the effects that Tenma had on the team may have lead to Minamisawa leaving, but it also lead to him finding new friends and his own soccer at Gassan Kunimitsu, and ultimately reconnecting with Raimon after that match. he wasn't exactly welcome to change at first, but acknowledging and vocalizing Tenma's role in changing his life for the better is proof that he's changed and grown a lot.
and on top of that, Raimon assuring him that no matter what he'll do or where he'll go, there'll always be a spot for him at Raimon? that they'll always be waiting for him? ahhh man it's so good, it's that promise of eternal friendship and support, even after everything, even though he was the one who left. and they acknowledge that Gassan Kunimitsu needs a player like him, that he belongs to that team too now, but that it doesn't matter which uniform he wears- he will always have friends at Raimon.