Madoka Tatsumi possesses grey hair and grey eyes. She became stepmother to Ryo Tatsumi following his biological parents' death in his childhood, raising him alone as his sole guardian. Over time, mutual romantic and sexual tension developed between them, though both consistently resisted acting on these feelings, preserving a relationship defined by restrained longing rather than physical expression.

Madoka later vanished unexpectedly, a disappearance ultimately linked to substantial financial debts owed to the Yotsuya family. Her indebtedness drove Ryo to enter servitude under Akie Yotsuya, the family head, seeking to alleviate Madoka's obligations. She eventually reappeared at the Yotsuya mansion, joining Ryo, Akie, the maid Fumi, and Akie's sister Reiko. Her arrival integrated her into the household's existing dynamics, notably following Reiko's specific summons to the estate.