I feel like these illustrations definitively explain how Miyuki was able to run over and lift Eijun up while still wearing his heavy catcher gear.
Officially, Miyuki weighs 71 kg and Eijun weighs 65 kg, but the guidebook only covers Act I, so Miyuki likely has more muscle now…
I feel like Eijun would excitedly drag Miyuki to every Noraneko Gang attraction on their days off because he saw the plush in Miyuki’s room and assumed he was a fan. Meanwhile, someone just left it there and Miyuki never moved it, so he just goes along to watch Eijun have fun.