高瀬 志乃

Sawa's younger sister and the main character's aunt.
She is a 34-year-old housewife with a family of three, including her husband and daughter.

Unlike her serious sister Sawa, she is a family-oriented person with a friendly personality.
While she understands her sister's situation, she is sympathetic to the protagonist who stays home alone and always invites him to dinner.

She teaches piano at home to neighborhood children.
The house is relatively wealthy and has a piano lesson room.