Kokichi Muta was a second-year at Kyoto Jujutsu High using Ultimate Mechamaru as his proxy to attend school. Kokichi himself could not due to the sickly and fragile body he was born with as a result of his Heavenly Restriction. Kokichi was a reclusive and reserved individual who resented being born without a future outside of the jujutsu world. Kokichi embraced the quiet robotic type persona while acting as a student through Mechamaru. Kokichi felt especially close to Kasumi Miwa.