Miss Mason (Sasaki Namie in Japanese) is the serious and somewhat stern English teacher and homeroom instructor for class 2-2 at Nanairogaoka Middle School. She teaches the main protagonists. She possesses brown eyes and long brown hair, typically secured in a high ponytail with a blue barrette. Her standard outfit is a pale yellow pantsuit worn over a blue top, paired with brown court shoes. Though seldom warm and not particularly friendly, Miss Mason exhibits patience and understanding towards her students, acknowledging that overcoming academic or personal hurdles can take time. Her strict actions are always well-intentioned, focused on student welfare. She reacts with notable reserve to peculiar events, accepting Emily and Kelsey's claim of illness despite their unusual sports equipment attire and showing minimal visible surprise during Emily's invisibility mishap, maintaining her composure. Information is limited strictly to her role within the series.