It sounds great! Melody is tsuki and harmony is yuki right? Your voices are very suitable for melody and harmony respectively, which make a very nice blend. The kajiurago was also awesome! May I provide some constructive criticism?
- I think the harmony was mixed a bit too loudly, sometimes overcoming the melody. Maybe just tune down the volume of the harmony a little while increasing the volume of the melody.
- Your timing for the first verse was just slightly off for a little bit.
- Wakana's part that goes "shirabe no youni" in the chorus was also slightly out of tune.
Overall very well done and I hope to hear more collaboration in the future!