Futakoi :

Souju is mild-mannered and ill-bodied, whereas Sara is rougher in her speech and more energetic. Nozomu meets Sōju while she was painting at the shrine, and Sara wanted him to be loyal to her.

Futakoi Alternative :

A foil for her sister she seems to be quiet and not outgoing like Sara. She is good at cooking, and also has a strong affection toward Rentarou.