The Anti-Orphan Squad is a team of HiMEs dedicated to protecting Fuuka Academy from Orphans. Although later in the story they cease fighting Orphans, they still retain their original name.
- Yuuichi Tate was brought to Fuuka Academy for the sole purpose of being Mai's and Natsuki's Key. He struggles with the fact that he can't do much since he isn't a HiME.
- Mai Tokiha - Mai prefers to not get others involved in her troubles, instead fighting Orphans and taking care of her brother by herself.
- Natsuki Kuga is a typically tsundere character, acting fairly aggressive to Yuuichi. She seeks vengeance for her mother.
- Mikoto Minagi is a HiME of unknown origin, taken care of by Mai. She carries her sword, Miroku, around with her.
- Akane Higurashi is a modest schoolgirl who loves Kazuya, her Key, but is too shy to use him.
- Midori Sugiura is the enthusiastic leader of the Anti-Orphan Squad who can best be described as a walking disaster.
The Ori-HiME Team was set up in response to the Anti-Orphan Squad's failures. In addition to fighting Orphans, they seek to eradicate the Anti-Orphan Squad. The name of the team is a pun on the legend of Orihime of the Tanabata festival.
- Haruka Suzushiro is the aggressive Chief Executive of the Fuuka Academy Student Council, as well as the leader of the Ori-HiME Team.
- Yukino Kikukawa is Haruka's assistant, often helping in enforcing the rules and fighting.
- Akira Okuzaki is Takumi Tokiha's classmate and his class representative. Secretly she is the ninja HiME.
- Nao Yuuki is a middle school girl who only cares about herself.
- The Three Scale Sisters are three sisters, each in a different year of high school, who wield triangular rulers as Elements.
Searrs Female Institute
The Searrs Female Institute is a separate school backed by the Searrs Foundation. The Institute sends students to Fuuka Academy as part of an exchange program.
- Shiho Munakata is Yuuichi's childhood friend who is obsessed with him.
- Alyssa Searrs is a young girl, seemingly Searrs' counterpart to Mashiro Kazahana.
- Sister Yukariko Sanada is the teacher in charge of the Searrs girls.
- Miyu Greer is Alyssa's guardian.
- Dr. Saeko Kuga is Natsuki's mother, who works for the Searrs Foundation.
- Mashiro Kazahana is the director of Fuuka Academy, responsible for the gathering of HiMEs and Keys.
- Fumi Himeno is Mashiro's secretary and maid.
- Takumi Tokiha is Mai's younger brother who is sick and hospitalized.
- Nagi Homura is a mysterious boy who seems to be behind the Orphans.
- Youko Sagisawa is the Academy's doctor, as well as a HiME with healing powers. Her Element is a Sthetoscope.
- Marie Antoinette is a QUEEN associated with flowers, based on the historical person Marie Antoinette.
- Yang Guifei is a QUEEN associated with cats, based on the historical person Yang Guifei.
- Kazuya Kurauchi is the boyfriend of Akane's and a friend of Yuuichi's.
- Masashi Takeda is Natsuki's self-proclaimed bodyguard.
- Aoi Senou is one of the students who watches the drama between Yuuichi, Mai, and Natsuki unfold.
- Chie Harada is another student who enjoys observing the love triangle of Yuuichi, Mai, and Natsuki.