Vol 1: Ch 54 - C and R
The Emergency Operating Room doesn't have any restrooms available because it only consists of 10 Emergency Rooms and a long hallway that directly connects to the emergency parking area in order to directly access and handle the Emergency Patients right away. The Chief Police orders his assistant to avoid anyone being near them since they're listening to a very internal matter that's no one and nobody can know it because it's a very private conversation for family matters while Rei finds the nearest restroom which is near in admission area, she gets in from one of the cubicles and get the clothes from the bag which was bought by the police officer.
After opening it, Rei commented on her thoughts 'Aiyah, that officer is not bad but well why did he buy me a dress? Am I really that girly to him? Ah, never mind that one and change first Rei'