"Seiko is an extremely cheerful and energetic girl who enjoys playing around with her friends. She often comes across as immature and crass, and makes over-the-top outbursts that surprise everyone around her, but her friends are able to put up with it. She generally tries to maintain this personality even while trapped inside Heavenly Host, though the grim reality of their situation nearly causes her to suffer from an emotional breakdown several times. She is not without a responsible side, however, which she developed after her mother disappeared two years ago in order to support her father and care for her three younger siblings. She easily becomes upset whenever anyone takes her feelings towards her mother's disappearance lightly." -Corpse Party Wikia