Seiji Utsumi, a below-average member of his high school's tennis club, is hopelessly in love with team captain and upperclassman Shou Iketani—a cute and bubbly prankster who frequently makes him the victim of her mischief. Unable to even look her in the eye without blushing, he often slips away from practice to watch her from afar.

In a fateful turn of events, Seiji is caught in the act of admiring Shou by Yuki Kurokawa, a popular and attractive girl in his club. As the only one who knows Seiji's secret, Yuki blackmails him into getting closer with Shou, gladly offering romantic advice along his path to finally confessing. But as Yuki observes Seiji's pure-hearted and gentle nature from up close, can she really accept only being a witness to his good ending?