Hallelujah spent his childhood in an orphanage with his best friend Akatsuki and another close companion, Nagi. He bears significant scarring from severe burns sustained in a past fire incident. During a widespread power outage that plunged Tokyo into chaos, both he and Akatsuki awakened supernatural abilities known as "Links."

His Link grants him control over rain clouds, enabling him to manipulate weather phenomena. He and Akatsuki subsequently joined Crown, a performance group formed by young people with Link abilities. Crown rose to prominence by protecting survivors and maintaining order within the lawless environment. As an active member, Hallelujah participates in Crown's daily operations focused on rescuing citizens and safeguarding them from threats like violent mobs.

He possesses a gentle personality and a powerful motivation to protect others, driving his actions within Crown. His closest bonds remain with Akatsuki, who affectionately uses the nickname "Haru" for him, and Nagi, who lacks Link abilities.