Beelzebub: Furuichi's Mother and Shouko Oga.

 This silver-haired lady is the outgoing mother of Takayuki and Honoka Furuichi.

Shouko is the mother of Tatsumi and Misaki Oga.  

Beelzebub: Azusa Fujisaka, Honoka Furuichi, and Isafuyu Kashino.

 Azusa Fujisaki is the easy-going and cheerful childhood friend of Kazuya.  She tries to brighten up any mood and is supportive of her friends.

Honoka Fujisaka is the younger sister of Takayuki.  She worries about the safety of her older brother as he is the only nondelinquent and has little fighting experience.   

Isafuyu Kashino is the shy and innocent priestess at Mapputatsu temple.  She helps train Aoi to fight a demon.