Kazumi Yoshida

Age: 15-16
Height: 160cm
Weight: 51 kg

Yuuji's classmate. She has a crush on him, but is too shy to tell him directly. However, she grows more confident and decidedly more direct in her advance after seeing Shana's feelings. She proclaims that she will confess, sparking a rivalry between Shana and her.

Pheles gives Kazumi a cross shaped hougu in the second season. The hougo would summon Pheles if there was any trouble happening to Yuuji/Johan. If she used it, however, it would take all her powers of existence. She was later taken to Seireiden by Yuuji to be used as a catalyst to the ritual reversing the effects of Khamsin's Tuning. After Shana, Wilhelmina, Chiara, Sale and the three remaining members of The Four Gods of Earth reached Seireiden, Shana witnesses Kazumi understanding what she needed to do at that time and activates Giralda, her existence disappearing.

(Source: Shakugan no Shana Wikia)