Hitagi, the main character of Hitagi Crab, is a weak-looking girl with an "incurable disease". She is in the same class as Koyomi, but she rarely speaks. During the period between graduating middle school and entering high school, she encountered a giant crab who stole her weight. Ever since, she has avoided contact with everyone else, and threatens everyone who discovers her secret. She became anti-social and was very different from her personality from when she was in middle school. She called herself a tsundere (but mostly as kuudere) and always speaks in an abusive style. At the end of Mayoi Snail, she admits that she loves Koyomi, and they start dating.
After the events in Tsukihi Phoenix, she overcame all of her trauma, and finally became a completely normal and cheerful girl. She starts referring to Araragi with a cute nickname, chuckling at small things and sending e-mails full of Emojis, although her sharp tongue is still there, but toned down. She seems to also have a father complex, getting excited when she uses her father's blanket, so much so that she can't fall asleep. Koyomi says that he loves Hitagi the most. She seems to not be on very good terms with Karen and Tsukihi.
In Hitagi End, continuing on the events of Nadeko Medusa, Koyomi is in deep trouble and to help him, Hitagi must swallow her pride and feelings again to ask Kaiki- the one person whom she truly despised and hated- for help.
