There are so many great songs that it would be impossible to talk about them all, such as the famous songs sung by the three female voice actors who play the heroines, Kugimiya Rie, Horie Yui, and Kitamura Eri (the OP of the first season, "Preparade", the ED of the second season, "Orange"), the ED of the first season, "Vanilla Salt" sung by Horie Yui, and the OP of the second season, "Silky Heart", which accelerates the story at a rapid pace.
eBay