It's spring break and the clubs are on the prowl for new members as students get ready to enter high school. During the break, there's been a tresspasser in the music room. Can the brass band club members figure out what she's been doing there?

Naoko volunteers to help Chika rehearse for the upcoming qualifying round, but wants her help in return. Her aunt has returned to Japan in search of information on her first love and goes to the school's First Love Sommelier for assistance.

The day of the district contest has arrived! When Haruta goes missing, Chika goes to look for him and runs into a writer who's interested in Mr. Kusakabe's past. Can the mystery of a lost dog's true owner appease the writer's curiosity instead?

According to the will of Mr. Kusakabe's former teacher, his granddaughter, Makoto, is the only one who knows the whereabouts of the key to his beloved piano. Can they figure out the secret of the key's location?

Mr. Kusakabe got an offer to conduct for the Hamamatsu Orchestra. Will he leave the Shimizu South High School Brass Band Club? Why did he skip on the performance as a conductor years before? Haruta and Chika follow him to find out.