If you want to learn more about each Side-Character, click here to see the list on Wizardess Heart Wikia.
Azusa's deceased little brother Tsukasa
Alfonse Goldstein, oldest of the Goldstein brothers, which was mentioned (but without saying his name) in Klaus' route. He has a fiance named "Elaine".
The new Headmaster of the Gedonelune Academy: Willem V Rembrandt
Aster - Guys father
Saella - a songstress who ends up teaching at the Gedonelune Academy
Prince Lucious, a cursed boy that is bound to life the Underground Labyrinth