Tsubasa Hanekawa (羽川 翼, Hanekawa Tsubasa) is Koyomi's classmate and the class representative. Koyomi describes her as "the class representative of all class representatives".
Hanekawa's catchphrase is: "I don’t know everything, I just know what I know."
Koyomi Araragi stated that he respects Hanekawa more than anyone else.
Hanekawa currently lives with her stepfather and stepmother.
Her biological mother was 17 years old when she got pregnant, the biological father is unknown because she apparently had many lovers. Before she gave birth to Tsubasa, she married another man who was a "workaholic". Right after giving birth, Tsubasa's biological mother commited suicide. The workaholic stepfather, unable to raise a child, remarried again to a woman who is Tsubasa's current mother. The workaholic father soon died from overwork and the current mother married another man who is now Tsubasa's current father.
Although it has since been resolved with the help of Shinobu Oshinoand at the cost of her own memories, the problems emerge again right before the school festival because of different stress. It was revealed by the bakeneko that the source of the aforementioned stress was her feelings for Koyomi. Despite Black Hanekawa possessing a female body, the spirit itself is male.
By the summer she has cut her hair and appears without glasses, either not needing them or perhaps wearing contact lenses. She appears in the Araragi household, objecting when Koyomi is about to hit Karen Araragi, since he had been upset when she revealed to him during Golden Week about her stepfather hitting her once. She then objects when he yells at Tsukihi Araragi. Both of his sisters come to his defense though, explaining that it is part of their usual sibling conflict and that they can handle themselves.
On her way to school, Hanekawa met a tiger that is able to talk. Her house also burns down which causes Black Hanekawa to appear due to the stress. Black Hanekawa goes to look for the tiger warning that if the tiger hurts Hanekawa, Black Hanekawa herself will kill the tiger.
It turns out that the tiger was a manifestation of Hanekawa's jealously towards the people around her. Just like Black Hanekawa, "Kako" which is the name Hanekawa gave to the tiger, is also a new type of Oddity. In the end Hanekawa reabsorbs Kako back into her body and fully accepts Black Hanekawa as a part of her. This leads to half of Hanakawa's hair becoming white and forming a stripe-like pattern in her hair, which in turn causes her to dye her hair black every morning.