Mashiro Tsukinomori (月ノ森 真白 Tsukinomori Mashiro) is a second-year high school student. She is Akiteru's classmate and cousin. Mashiro is shy around strangers. However, she has a cold attitude and poisonous tongue only towards Akiteru. She is also secretly a scriptwriter as part of Akiteru's 05th Floor Alliance.