First-year high school students Kana, Reimi, and Hibiki are apprentices at the Karasuma Phoniatric Clinic, where the power of healing through song is combined with conventional medicine. One day when the girls' teacher is out, one of the clinic's patients takes a sudden turn for the worse. Is there nothing these apprentices can do to help?

After a study party and lots of prayer, the girls take their provisional license exam! But the minute the test is over, they feel completely drained. Ria takes them out to the town's annual sports day to cheer them up... where they happen to run into Sonia, who has competition in mind!

The girls of the Karasuma Phoniatric Clinic visit Hibiki's family in the country. While wandering the countryside, the girls' friendship grows deeper as they learn more about Hibiki's past and the reason they each became healers.

The culture festival is a huge success! ...Or so it appears. At the last moment, something happens to threaten the final stage performance. Can the healer girls step in to fill the hole in the schedule?!

The girls have been asked to support Ria during a surgery... but the patient is Ria's old teacher, and the hospital's director! Despite their nerves, the girls are determined to give it their best shot!

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.