Matoi Tsunetsuki is a student in Nozomu Itoshiki's class in the anime and manga series 'Sayonara Zetsubou Sensei.' She is known for her obsessive and stalker-like behavior, quickly becoming fixated on people and following them relentlessly. This trait often leads to comedic situations and misunderstandings within the series. Despite her odd tendencies, Matoi is portrayed as earnest and sincere, making her a memorable and unique character among the eccentric cast of students.