Finding JAV code movie about a girl in uniform masturbate on the sofa

I saw it once on the internet and can't find it anywhere on the internet so I put a default image. Sorry about that.

I remember it started with a girl wearing uniform sit alone in a quite dark classroom. Then it transistion to the room have music instrument in it (If I not wrong, she play the flute in that room too). After that, she masturbate on the sofa athe same room. Her uniform have a pin if I remember it well.

Thank you so much for the person who figure it out.