The three apprentices of Ria Karasuma are about to become true healer-sisters, but as the test approaches, they can no longer sing harmoniously. Ria therefore offers to send them to a training course, under the benevolent supervision of Aoi.

Having passed the exam to become a C-rank cured-sister, the apprentices of the Karasuma clinic go on a training course each on their own. Reimi will train in Sonia's clinic and Hibiki will work in the hospital. Kana goes much further, to the United States, to pursue her dream.