Hajime Tabata, Director of The 3rd Birthday, tweeted more about the costume damage system. When Aya rests at a save point or accesses a headquarters her clothes automatically mend themselves. This also means Aya’s hit points are healed when she reaches either of those destinations.
Aya’s clothes are also restored after an overdive, the ability that lets Aya jump from one soldier’s mind to the next. This makes sense since each unit on the battlefield has their own life bar. Whether Aya controls them or not, units can take damage from nearby Twisted.
After Tabata talked about all of this he asked Tokyo Game Show attendees to play the game normally instead of just testing out the battle damage.