Swimsuits go soaring in a beach episode gone awry! Then, after Sakaki gets a nasty cold, she spreads it to Natsuki. Now the trio of unapologetic brocons Sakaki, Sakurako, and tomboy Amamiya Aki must compete to play the perfect little sister and nurse Natsuki back to health! But will a forgotten childhood promise snatch Sakurako’s place as childhood friend away from her?