Hello Andrew,

This is a gentle and beautiful song reminiscent of 1960s pop.
The bass's semitone descending progression starting with E strongly evokes that era.
Your singing touch is also very soft and pleasant.
Pre-chorus ends with B7 chord and Chorus begins with Em chord, so theoretically this could be said to be a modulation to E minor.
The cross-stick effect in the video also fits this song very well.
Enjoyed my listen and watch a lot.

Best regards.

Shigeki Adachi