Mariya Mikhailovna Kujou is a second-year student and the student council secretary. Her nickname is Masha and she is the older biological sister of Alisa Mikhailovna Kujou. She is one of the two beauties from her school year. She is popular for her looks and motherly gentle aura. She is called the "Madonna" of the school because of this. Masha purposefully acts like an airhead around Alya because she doesn't want to compete with her. She acts like this because she loves her sister very much. In reality she is very mature and serious deep down inside. Masachika finds it very hard to read her because of this.

Spoiler

Masha turns out to be Maa-chan, Masachika's first love. They were childhood friends and often played together until Masha had to leave for Russia. Masachika never recognised Maa-chan in high school because she had blonde hair and sapphire eyes when she was younger. She continues to love Masachika even now but takes a step back because of her younger sister's feelings for him.