Yukiya Asagi and Miku Sakura are childhood friends. When they were in sixth grade, they started a strange game: they would say “I love you” to each other, with the goal of making the other blush. Whoever blushed lost. Four years have passed, and both are in high school, but their childish game continues. Each one is constantly trying to outdo the other.
But times are changing. Now, when they say “I love you” to each other, their hearts begin to race, and these words are no longer just a game for them. True love has blossomed in both of their hearts, and they no longer want to remain mere “childhood friends.” But the fear is that if this game ends, what will happen to their relationship? Because of this fear, neither is ready to take the first step.