Hyoudou Issei’s wife is Rias Gremory.

Rias Gremory is the sister of Demon King Lucifer. She is the successor head of the superior demon Gremory family and the former head of the Occult Research Department of Kuoh Academy. She fell in love with Hyoudou Issei and later became Issei's wife. The rank in chess is the King.

Voiced by: Hikasa Yoko

Titles: Red-haired Killer Princess, Switch Princess (named by the monkey), Minister (named by members of the Occult Research Department), Red-haired Devil Breast Princess, Breast Battery (named by Azazel), Crimson Dragon Killer Princess

Race: Pure-blood Demon

Class: Superior Demon, 72-Pillar Noble Gremory Successor to the head of the Duke's family

Occupation: student

Grade: third grade to first year of university

Husband, lover: Hyoudou Issei

Familiar: Red Bat

Class; King

Magic Characteristics: Power of Destruction

Trick:

Destroy the Demon Star (Extinguish Star): A magic bullet that concentrates the power of destruction, regardless of resistance or weakness, and can destroy everything without being affected by any factors.

Crimson Extinct Dragonar: The fusion technique used when fighting alongside her husband Hyoudou Issei, allowing the Sekiryuutei's flying dragon to attach to Rias, creating a female version of Crimson. Dragon Emperor's armor (boosted gear scale mail). Later, Xenovia, who was also Issei's wife, also developed a similar fusion technique with Issei - the True Red Destruction Dragon Knight.