Kuukai Souma  

, 相馬 空海

Jacks Chair is an energetic and athletic individual who serves as captain of the Soccer Club. He has graduated, which led to his replacement. In the school magazine, he was mistakenly thought to be dating Amu due to a picture taken by a student after she emerged from her Character Change and lost strength. Saaya became angry upon seeing this photo. Jacks Chair and Daichi once underwent a Character Transformation with the help of the Humpty Lock, becoming "Sky Jack." During one of their transformations, Daichi shouted "Kick, Stack, Trap and Shoot!" When Kukai graduated at the end of the school year, he left to attend middle school. However, he occasionally returns to visit the Guardians. Jacks Chair and Utau have formed a strong friendship in both the anime and manga, causing suspicion among some characters like Yaya.