Furthest from the main hospital, but still connected to it, is an area blocked off completely to anyone apart of the Medical hospital. Where as, here, in the Psychward sector, is those who need therapy to recover from, perhaps, mental disorders, or just a traumatizing event. In most cases, enemies who needed healing yet kept at bay from others will be kept here in Isolation Rooms manned by guarding Shinigami. Only a select few are allowed to work within this area, having to undergo a test by Daisuke's discretion to ensure work safety and ethic, and to make sure her subordinates can survive these type of conditions. And all the more reason for only the Taicho and Fuku-taich to be allowed entrance within the area. Only way to enter is if you're with the Taicho or the Fuku-taicho