She was a participant in The Tragedy of Hope's Peak Academy. She and Taro planned to commit suicide together, but instead they were murdered by Sōsuke Ichino in an envious rage after he was forced to kill Kiriko Nishizawa.
Tsubasa has long, light green hair which reaches down to her waist. It's left mostly loose but some of it is tied back with a hair ornament in the shape of a butterfly surrounded by leafs. Her eyes are a pale blue and her skin appears fair.
Tsubasa wears a customised Hope's Peak uniform consisting of a white dress shirt, a standard red bow, and a dark blue skirt. Additionally, she wears black, thigh high stockings and a low cut, caramel colored cardigan. Her shoe wear are typical school shoes.
Not much about Tsubasa's personality is known, though she appears to a polite young lady, and in her character design notes she is portrayed with a gentle smile. When faced with her classmates fighting, she brings her hands close to her mouth in shock and bears a worried expression. She can be heard audibly gasping when Ryōta Someya picks up a shotgun.
She did not appear to fear death while setting up a suicide with Tarō, but is shown horrified at his death and calling out in pain as she is murdered by Sōsuke.
Junko Enoshima gathered all of the members of the Student Council and Izuru Kamukura in the old Hope's Peak Academy school building. When the Killing Game began, Tsubasa and Tarō fled into the hallway. They both decided to commit suicide and held a gun to the other's chin. Sōsuke stabbed Taro from behind, who fell on Tsubasa, ultimately trapping her. Sōsuke then pounded the sharp weapon through Tarō's body into Tsubasa's using a shovel. She screamed and begged to be left alone, but Sōsuke continued to pound the object deeper into Tsubasa until she dies.
They are shown to be standing closely together at the back of the classroom during the Student Council introduction, and in light of the death happening around them decide to commit suicide together. They point guns under each others' chins most likely in an attempt at a quick and painless death, just moments after they share a hug and reassure themselves, with Tsubasa commenting how they should bring it "to a beautiful end".
There is not much else known about them, though they appear to be close and care for each other mutually, possibly implying their relationship as romantic.
- Her given name, "Tsubasa" (つばさ) written in Kanji (翼) means "wing."
- Her surname, "Kamii" (紙衣) means "paper clothing."
- The double suicide could be a reference to Romeo and Juliet, as the death of two young lovers is widely considered to be romantic and tragic.