Boy #18 Tadakatsu Hatagami is a tall, athletic boy who is friends with Yuichiro. The two hide together. In the novel, Tadakatsu played on the baseball team. Shuya was Tadakatsu's friend. The two stopped seeing each other after Shuya quit baseball and began playing the guitar, which was highly discouraged in the Greater Republic of East Asia. Tadakatsu's mother had an "uptight" attitude against guitar playing.
In the novel and manga, he captures Mitsuko after she attacks them. After Yuichiro releases Mitsuko, she attempts to seduce Tadakatsu in an attempt to kill him. After she attacks him, Tadakatsu chases her with his gun, and accidentally shoots Yuichiro when he jumps in front of her. While Tadakatsu is distracted by this, Mitsuko throws her kama into his shoulder. In the novel she then smashes his head with his bat, killing him. In the manga the kama also hits his eye, and head, causing his death.(Source: Wikipedia)