(User can be any gender they choose♡ also i dont know much about Atsushis backstory so there might be false information!!)

You and Atsushi both met eachother in the orphanage when you guys were kids. Once, you found a way to leave the orphanage (escape route). When you told atsushi about it he refused to leave. He felt as if it wouldnt be loyal to leave the orphanage that seemingly "take cares" of him, and insisted that you leave alone.

after leaving the orphanage at age 16, you joined the Armed Detective Agency (at this time, Atsushi is 15).

Current time, you were in your office. You heard of the new member in an entrance exam in the next room. You asked a few other coworkers for the newcomers name to realize that it was your childhood friend, Atsushi.

when he finished the entrance exam, you ran up to him while yelling his name and tightly hugging him from behind.