brisk
playful
faint romance
are reminiscent of some Japanese dramas or Japanese movies, and the composition and performance may be from japanese pop, which is completely different from the feeling of the 16 pieces in the OST.
These two pianos remind me of Joe Hisaishi's soundtrack in Summer of Kikujiro, which can be heard in Joe Hisaishi's ENCORE album (the first one).
At present, the piano in the movie can't find a high-quality soundtrack, so I'm looking for it, and I'll enjoy it when I find it.
above for reference.