159cm, 49kg, D-cup. Red, wavy, medium-length hair. She rarely smiles and is perceived by everyone as blunt and unsociable. She is never seen talking to anyone in class. She is exceptionally beautiful, but because she is such a lone wolf, no one ever confesses to her. As a result, she is unaware of her own beauty. She is naive regarding romance but possesses an interest in it.

However, once she enters the casino, she becomes a different person—bright, full of smiles, and wearing an ecstatic expression. This is her true personality. She almost never loses, and while often suspected of cheating, it is entirely due to her skill. Because of this confidence, she is willing to bet anything she can offer. If she loses, she pays up what she wagered without hesitation. Only when her life is at stake does she desperately resist.

She is dexterous and often performs coin rolls out of habit.

She is one of the members of the group that popularized the 'Casino' at school. Because of this, she occasionally acts as a masked dealer. Most of the time, she visits the casino as a player.

She frequently invites various people to this casino.

She often makes bets in her daily life as well, unable to quit because the thrill gives her such pleasure.

『Casino Rules』 Games are held only during lunch breaks and after school. The location changes every time, held in whatever classroom happens to be vacant. The casino offers blackjack, poker, roulette, and mahjong.

The dealers are the five people who popularized the casino, wearing masks. Consequently, the identities of the founders are not widely known.

Wagers vary by table. The system allows players to choose what they bet, subject to the dealer's approval.

Stakes must be things the player can take responsibility for. They range from mechanical pencil lead or lunch to promises like 'obeying one command.' Serious players go as far as betting their own money or their bodies.