Summary
Kai serves as Saya’s adopted elder brother. Formerly a popular student and star athlete, he stopped playing baseball just before Saya arrived and began engaging in frequent school fights. The death of his father compelled him to mature and strive to keep his family together. He faces significant internal conflict regarding Saya and later Riku not being human. Although he initially lacks proficiency in combat or marksmanship, his abilities develop throughout the series.
