You-Geon, a high school student, is saved from drowning by a mysterious girl his own age. Indeed, this girl is a North Korean agent trained to kill. The encounter which will completely change You-Geon's peaceful life means that this mysterious girl never leaves You-Geon alone for a second worried he might reveal her secret to someone. The href='http://atm.zenaku.net' onclick="window.open(this.href, '_blank'); return false;">ATMosphere at the high school will never be the same again..