Soleil's debut in Episode 37 after Ran left tristar to join Ichigo and Aoi was one Aikatsu S1's greatest moments (and God knows that there are many): finally the main trio have their own unit, with some great sun-themed costumes and the really catchy insert song "Diamond Happy" which was also an awesome opening for the second half of the season.

Definitely one of my favorite episodes of Aikatsu S1.