Ren Seto

As San's devoted mother, she plays a pivotal role in supporting both San and Nagasumi while frequently acting as a stabilizing force for her husband. She possesses a playful personality, often finding amusement in teasing Nagasumi due to his adorable nature. Her presence in the story expands significantly when she transfers to Nagasumi's school, officially taking on the important responsibility of serving as the institution's new school nurse.