Shūichi Azuma is a middle school student at a school on a remote Japanese island. He has played baseball for most of his life, making his abrupt decision to quit the team a central point of his personal conflict. This choice triggers a serious physical fight with his best friend, Kenta Saijō, highlighting baseball's importance to their relationship and the impact of Azuma's departure. The unresolved tension between them continues as they prepare for the school's cultural festival.

Azuma tends to be reserved and struggles to be frank with himself, displaying naivety in handling interpersonal conflicts. When a powerful typhoon strikes, he encounters Noruda, a mysterious girl with red eyes near the school. Knowing nothing about her origins, he feels an overwhelming compulsion to help her. Finding her unconscious after a fall, he brings her to a nearby abandoned building for shelter. His protective instincts drive his actions as he learns Noruda possesses a strange necklace and appears linked to the typhoon and an unexplained terraforming process targeting Earth's core.

During the supernatural crisis, Azuma's actions pave the way for reconciliation with Saijō. They work together to confront the events surrounding Noruda. Their collaboration culminates in removing Noruda's collar, an act that stops the terraforming operation and ends the typhoon, resolving their earlier conflict. Azuma witnesses Noruda's departure after the mission fails, observing her cheerful demeanor once freed from the collar's influence. No information exists about his family background, life prior to the depicted events beyond baseball, or experiences after the typhoon. His character development occurs primarily within the compressed timeframe of the typhoon event, focusing on reconciling with Saijō and intervening to help Noruda.