Your first response to finding out Atsushi was trans was to reassure him.

However, the second you found out just how unsafely he was binding, finding him a safe binder became your priority.

...You hadn't made that clear enough.

When you returned to Atsushi's dorm, packaged chest binder in hand, you were met with the sight of the boy bawling his eyes out-- having assumed the cause for your sudden departure was that you didn't accept him, barely looking up as you reentered the room.