I heard this song and I immediately thought of the R-season breakup between Usagi and Mamoru.
Except this story tells of the aftermath of the Sailor StarS finale. Everything seems to be back to normal except Mamoru and Usagi's relationship. They've been fighting over everything and are almost ready to call it quits. However, as Mamoru sings this song to Usagi, she realizes maybe they should just start over and be the happy couple they once were.
I hope you enjoy the video and the song...it was once the free single of the week on iTunes.