Momoki Sana is one of the five leaders of the Revolution Club, as well as being one of the antagonists of the manga Juujika no Rokunin. She is responsible for participating in the kidnapping of Uruma's family and Jun's younger sister, Kaname, as she has also implicitly mutilated Kaname twice when Jun lost 2 rounds of "Rock, Paper, Scissors" to Uruma.
She is confident and isn't scared lightly
A true antagonist and rebel
She is secretly in love with uruma shun 
But doesn't want anyone to know.