under the radar

sun-yung, a senior instructor who doesn't care about affairs with pretty girls, and myung-jin, a young instructor who spends his days picking up trash because of such an idiot-like senior. myung-jin falls in love with a beautiful student yura' in an advanced class where he accidentally entered as a pinch hitter, and afterward, he sees sun-yung, who starts flirting with yura, like a thorn in his eyes under the cool swimming pool, a secret love game begins!