|Talent|| Body Heat Control|
|Relationships|| Hiruko Nana (best friend)|
Tomu Shirasagi (love interest)
Mayo Hanasaki has long pale blue hair and wears a low cut dress that reveals much of her large breasts when we first see her. Her hands are riddled with numerous cigarette burns caused by her father. She wears a variety of outfits in the series.
Mayo has a cold air about her, giving off vibes of being ethereal like a witch, which she claims to be. Because of her bad childhood, she has become distant with everyone around her, viewing herself like a poisonous flower that hurts others and would eventually wither and die. Despite her sedcing air, Mayo is overcome with a deep loneliness and has no concern whether she lives or dies. After meeting Tomu, her cold heart began to melt, giving her reason to hold onto life once again.
Mayo grew up in a harsh environment with an alcoholic abusive father who beat on her for no reason. Her mother was no better as she selfishly abandoned Mayo to said father to save her own skin. Mayo's father later died of poisoning, then was sent to Shishido Academy where she became part of the Abidani Seminar.
At the start of the dice games, Mayo, along with Hiruko and Yoizame, are selected to face off against "Team Shirasagi". Mayo was the one who dueled against Tomu in the dangerous "Judgement Fire" game, where the loser would be crushed to death under a huge pot of flaming coal. Using the witch dice, which are rigged to be able to change their centers of gravity with heat, Mayo managed to get Tomu's pot dangerously close to him, practically ensuring her victory. To her shock, he was able to turn it around after finding out the trick behind the witch dice (and after nearly burning himself to death). In an all or nothing last round, Mayo rigged the last two dice to roll 1's where Tomu needed a 6 to win. Again, to Mayo's shock, Tomu's die rolled a 6 as he had used sleight of hand to switch out a die that would roll a 6. Mayo accepts her loss, but then grabs Tomu, saying she planned to take him with her just as Abidani dropped the flaming coal pot on them. It was revealed that they survived, having opened up a secret hidden passage underground to her hidden garden. She points out to Tomu that the outcome of their match wouldn't have mattered to her anyway, since even if she did win, she had nowhere to go back to, not to mention that her deteriorating health will cause her to die in a short time. Mayo also reveals to Tomu that his father, Yumeichiro, was indeed in Shishido Academy, and that the one who held him there was Abidani. Mayo tells Tomu that her match with him was probably the only happy moment in her life where she felt alive, then proceeds to commit suicide by downing a vial of poison. To her surprise, Tomu immediately grabs and kisses her to suck out the poison from her mouth before she could swallow. He tells Mayo that she shouldn't throw her own life away and that she is no longer alone, striking a chord in her heart. Mayo falls for Tomu, finding reason to cling to her life and agrees to seek hospital treatment for her condition.
Mayo would return later after the flag capture challenge. Having been invited by Tomu to a hot springs resort hotel along with Mizuhara, Natsumi, and Yuka, Mayo tells everyone about the "Class Reunion" held by the Shishido Foundation. She reveals that this "Class Reunion" is where Abidani reigned supreme as an undefeated gambler, and that Yumeichiro lost to him.
Mayo is a skilled botanist, tending to many types of poisonous flowers in a secret garden of hers. Her health began to slowly deteriorate because of this, and later she gained the ability to regulate her own body temperature.
Ironically, Mayo is also a skilled healer, as she was able to heal Tomu's blindness after he got blinded in his first fight against "Mr. X".