Miyuki actually supports Eijun as much as he supports Furuya though! he practice with Eijun on off seasons, I don't know if also practice Furuya but he and Eijun are working on new pitches so it's safe to say Miyuki also helps Eijun. I think Miyuki interact more with Eijun than he does with Furuya?
Miyuki has always been Sawamura's biggest supporter, he was the one that made Chris stay and train Sawamura by making curious about Sawamura's talent. Not only that- wasn't he the one who asked chris to help Sawamura through his yips when he couldn't help him anymore?
for some reason, I don't really like miyuki... maybe because he always support fuyuki.. even when he made promise with eijun, he just broke it when fuyuki ask to practice some more... so i really hope okumura will become eijun fix partner and outwit miyuki and furuya ... it's not like I hate miyuki, it just he seem so calculating and only prioritize the one he think is the best.
and since beginning I thought this manga is about sawamura but in my eyes, it seem like the author focusing more on furuya... I also thought that gradually it will shift more toward sawamura.. but unfortunately it seem more focus on furuya growth.. I don't know how author will change it later and make sawamura become the center of the story instead of furuya... I just hope furuya will not end up having an injury or any misfortune thing and make sawamura become a center just because of that... ヽ(`Д´)ﾉ