Setsu appears to be an elderly woman.
Setsu appears to be very kind and friendly towards her grandchildren. However, she does not tolerate Magane attraction towards younger women and will go as far as using Clear Fall Water on him to prevent him from entering Hysteria Mode. She believes you should take care of your own things.
Setsu was born to a promintent military family, where she was raised to be an expert in martial arts. Despite this, she attended a school for floral arrangement and later became a floral designer. At some point, she met Magane Tohyama and married him for unknown reasons. After their marriage, it was reported that the Tohyama Family martial arts ability increased to a considerable degree as a result of her sharing her family's knowledge. Later on, Magane and her would have a son, Konza.
- Setsu has similar hobbies and taste in music as Shirayuki Hotogi.
- Setsu gave Kinzou his name just like how Kinji gave Kaname her name.
- Every recipe she makes is authenic Japanese.