Tsubomi is a shy and timid introvert who usually keeps to herself, hesitant to speak openly unless approached first. She often worries over small things and is easily worked up, especially when scared or trying to handle more energetic people like Erika. She strongly wants to shed this aspect of herself and over the series manages to become more easygoing and willing to speak her mind thanks to Erika's friendship and encouragement, until she became confident enough to accept her negative qualities.