Hikaru Tachibana is a second year at Kuoh Academy known as the Dark Emperor. After being killed by a Fallen Angel, he is brought back to life as Rias Gremory's Devil servant. But, Issei Hyoudou took up her eight pawns. So what piece is he? An experimental one called a Vanguard. As such, he will lead the way to victory for Rias' Peerage. Slightly OP OC OCxHarem

Yuto Tachibana is an ordinary 16-year old boy that likes to be cut off from people. However, he was selected to be a student for Hachimitsu Academy which was previously an all-girls school but has now accepted 6 boys to enter this year. He has no problems with this until he meets Meiko Shiraki, an old childhood friend of his that has gone through some serious changes.