Seiko Ayase

Seiko Ayase is Momo Ayase's grandmother and a major character in Dandadan. She's a renowned spirit medium (often going by the alias Santa Dodoria) with extensive knowledge and experience dealing with yokai/spirits and the supernatural. She serves as a mentor and supporter to Momo and her friends as they face paranormal threats.

Despite being a grandmother, she has a strikingly youthful appearance, looking like an attractive, slender woman in her prime with long snow-white hair (usually tied in a large topknot) and red rectangular glasses.

Her personality is phlegmatic and laid-back, but she speaks in a very blunt, uncouth, and unladylike way. She's often immature or teasing, yet deeply caring, selfless, and willing to help others when it counts—showing wisdom, courage, and strong protective instincts toward her family and those in need.