Is Koe Koi coming back?

Yoshioka Yuiko begins the first grade in high school. She gets sick with the cold and stays in bed. At that time, she gets a phone call from class president Matsubara. Yuiko becomes flattered by his kind voice on the phone. The next day, she goes to school and meets Matsubara. He is a mysterious boy, wearing a paper bag over his head. Her high school days begin with pounding heart.