Tokine, aged 16, is the 22nd Kekkaishi of the Yukimura family. She has a scar on her right hand from protecting Yoshimori in their childhood. Despite her excellent accuracy and precision, her kekkai are weak and short-lived compared to Yoshimori's powerful ones. Initially, she tries Masamori's technique of stacking multiple kekkai around a target but finds it too exhausting. Later, she develops narrow "spears" with her kekkai that can impale and trap enemies, compensating for her lack of brute strength.
Tokine also possesses the ability to manipulate kekkai and space. This is evident when she manipulates Yoshimori's kekkai to pass through it and uses a portal created by an enemy to enter his dimension during a kidnapping incident involving the Yagyou. While she admires Yoshimori's potential, she often becomes frustrated by his poor control and laziness. Throughout their childhood, she has protected him numerous times and enjoys teasing him, though she remains unaware of his feelings for her. As the story progresses, signs of deeper affection towards Yoshimori become apparent, such as when she slapped him unconscious for fighting Kaguro alone and punished him for going to Okuni without her.
Despite being considered the weakest Kekkaishi, Tokine is noted for her ruthlessness. Her pragmatic approach is seen when she disregards the health of Hachiouji Kemiya while he is possessed by an ayakashi and when she performs a forbidden metsu on a god from Shinyuuchi who attacked Karasumori. However, her biggest fear remains cockroaches.
