Misuzu Kawazoe was Yuyu Shirai's Schutzengel at Yurigaoka Girls' Academy before the main story. She perished fighting a Huge two years prior, an event that deeply scarred Yuyu and fundamentally shaped her character.

Their relationship held intense, complex emotional layers. In a pivotal flashback, Misuzu confessed her love to Yuyu, simultaneously expressing fear these feelings might drive her to harm her. During this confession, she clasped her hands around Yuyu's neck as if to strangle her, pleading for Yuyu to kill her if she ever lost control. When Yuyu replied she wouldn't mind if it was Misuzu, Misuzu sealed away those memories. This dynamic featured Misuzu comparing Yuyu to a fragile, beautiful "drop of morning dew," while wrestling with violent impulses she fought to contain.

Misuzu wielded the Rare Skill "Charisma," a significant ability later manifested by another character. Research within the series indicated this Charisma skill influenced the Huge, contributing to their evolution. Her weapon, the Dainsleif, became a critical artifact after her death. Its Magie Crystal Core retained battle logs of its users, including Misuzu's unique combat style. This allowed entities like Gozen to perfectly replicate Misuzu's techniques to manipulate Yuyu, exploiting her unresolved trauma and grief.

Her legacy maintained a potent psychological hold on Yuyu. Fragments of Misuzu's personality or influence manifested within Yuyu's mind, overwhelming her at times and causing emotional instability. This lingering presence triggered periods where Yuyu relived traumatic memories or became unresponsive to current events. Misuzu's actions, especially her death and the burdens placed on Yuyu, directly motivated Yuyu's initial isolation and her subsequent journey toward healing.

Her name reflects her character: "美" (mi) meaning "beautiful," "鈴" (suzu) meaning "bell," and the surname "Kawazoe" combining "川" (kawa) for "river, stream" and "添" (soe/zoe) implying "annexed," "accompany," or "attach."