The Hyuuga twins won't stop arguing with each other, even when it disrupts their classes. It's gotten so bad that they're at risk of having to repeat their first year of high school. Fortunately, the principal has a solution—join the boys choir!

The principal has found an interesting video on NewTube. She has Rika and Haruo listen to it. Haruo decides that since the singers are more "yes" than "no," he needs to find them and add them to the choir. But the choir will have to catch them first!

Now that the choir has ten members, it's time to get serious about entering the Kanto boys choir competition! The boys find out that last year's national winners are performing at a festival, so they go to check them out. Then they run into Maiden's dad!

The choir heads into the mountains for a singing training camp, but when they arrive, they discover that the site they'd reserved is already being used by a rival school! Meanwhile, Haruo refuses to do anything but...look for kabocha squash?

It's time for the choir to start rehearsing in earnest, but the AC is broken and it's too hot to think. They move to somewhere cooler, and Rika gives them a song to hone their rhythm. Then, they're swept up in a series of inexplicable events!

IT hasn't been to school for a whole week. The whole choir is worried. Haruo spots IT in the street and drags him to choir practice, but he doesn't seem himself. Rika and Haruo visit his home to check on him and are shocked by what they find!

The choir is still reeling from the loss of one of their members, but they're determined to practice as hard as they can for the upcoming competition. Unfortunately, their parents aren't happy about the choir's late hours and they complain to the school!

It's finally time for the Kanto competition. Day one is the set piece performances and all of the choir's rivals are there. Will everything go exactly the way they've rehearsed, or should they expect the unexpected?