Kasumi Miwa is a second-year student at Kyoto Metropolitan Curse Technical College, hailing from a poor family with two younger brothers. Her drive to become a jujutsu sorcerer is largely financial, motivated by the need to support her siblings. She possesses long light blue hair that falls past her shoulders, featuring asymmetrical bangs and dark triangular eyebrows. Her standard uniform includes a black long-sleeved jacket over a light-colored button-down shirt, a black tie, pants, socks, shoes, and a belt to hold her sword. For training, she wears her hair in a ponytail and a dark-colored tracksuit. Kind-hearted and hard-working, Kasumi exhibits a restrained and down-to-earth demeanor. She often displays vulnerability and low self-esteem, openly calling herself useless and fearing her weakness burdens others. Despite orders, she felt uneasy about her class's attempt on Yuji Itadori's life and later apologized. She idolizes Satoru Gojo and serves with a respectful, professional attitude as occasional secretary to Principal Yoshinobu Gakuganji. As a Grade 3 sorcerer without an innate technique, she relies on New Shadow Style swordsmanship. With moderate cursed energy, she employs Barrier Techniques, including New Shadow Style: Simple Domain—a 2.21-meter diameter circle that auto-intercepts intruders. Her Batto Sword Drawing technique uses cursed energy around the sheathed blade to generate exceptional drawing speed. During the Goodwill Event, Maki Zenin defeated and disarmed her. In the Shibuya Incident, she joined Kyoto peers in attacking Kenjaku (Pseudo-Geto), making a binding vow to enhance Batto Sword Drawing by swearing never to swing a katana again. Kenjaku caught and crushed her blade, nullifying the vow but leaving her unarmed. She later acquired another katana, which also broke. Her relationship with Kokichi Muta (Mechamaru) was meaningful; she developed feelings for him and was the only male classmate she did not fear. She witnessed his death while he battled Mahito remotely and weeks later heard his final words through a communication device, weeping at his message. In the recent battle against Sukuna, she used Simple Domain to shield Maki Zenin from the sure-hit slashes of Sukuna's domain expansion. Her primary katana became a semi-cursed tool after prolonged imbuing with her cursed energy. Maki broke this sword during their confrontation. Another katana she used later met the same fate against Pseudo-Geto. Her surname incorporates the kanji for "three" and "ring/loop," and her first name means "mist." She placed 11th in the manga's first character popularity poll. Her hobbies include saving money, her favorite dish is stew, and she dislikes Chinese parsley.