Desperately looking for a Japanese movie I watched a few years ago

I’m trying to find a movie I watched years ago, but I barely remember the details. It was a Japanese live-action movie. The title was short and simple, maybe around 3 words. The story was about a girl who was possibly living with her brother, and there were probably around 3 high school boys involved.

The whole movie had a very melancholic, almost poetic atmosphere. The girl was lonely, I remember a lot of blue/dark visuals, a very dreamy feeling, and maybe some scenes with bicycles.

The soundtrack was mostly classical piano music. I strongly remember hearing “Für Elise” by Beethoven (and some more similar stuff kinda reminding me of drowning love the movie as well as the music) multiple times throughout the movie.

I think it was released sometime between 2010–2019 and not sure but I think it’s not as well known (I might be wrong th)

Does anyone know what movie this could be? I would really appreciate any suggestions!

pls