Prince on the White Horse Episode 4

In the past, Amane Ōtori comes back from a horseback-riding competition and is greeted by the students from Spica, the school she attends. Hikari and the other Saintly Chorus members perform for Amane. Hikari messes up and is very flustered. The next dawn she sings the song that she messed up at and Amane and Hikari devolop a relationship.