Throughout his childhood, he lived in an orphanage from which he was kicked out due to an accident he unknowingly caused. He possesses the ability of the lunar tiger, which turns him into a white tiger. Although he doesn't know how to fully control it yet, he knows most of it, though not the complete form yet. He entered the Armed Detective Agency, it all started when he saved Dazai from drowning in a river. And Atsushi is 18 years old.
