Have you ever heard the sound of falling in love?

"I love singing, but this is a secret to everyone."
Ao Sakurai, a first-year high school student who is shy and always reads the air around her and acts.
Her secret hobby. It's singing a song.
Ao sings freely alone in an empty classroom. She thought that this kind of daily life would continue as usual ... without anyone noticing.
The next day, Ao was preparing for a graduation ceremony in the classroom with her friends. Suddenly, Shin Narita, the student council president and a popular second-year student at the school, came to her. He is blonde and handsome, and Shin is the exact opposite in appearance and content.