Cast: LEE Soo Hyun

Weak, bullied, and pessimistic about life, thats Setsuna Kashiwagi. On the verge of jumping off a bridge, a mysterious man appears behind him and offers the contract 10 million yen in exchange for your life in a year. Skeptical at first, he accepts. Waking up the next morning, thinking it was just a dream, he notices 2 beautiful women sitting beside him. They are Kanna and Rena, Oni princesses here to claim his heart in a year.

In the future, an energy source called "Life" has become incredibly important. Certain people are able to synchronize with devices called "Sai" which gives them the ability to extract "Life" and have super powers. These people are known as "Sai Takers." Within the "Sai Takers" there is an even smaller group, "Original Takers." "Original Takers" have a contract with a magical device, and they can manipulate "Life" without the use of a "Sai." These powerful people are also immortal, and they only die if they run out of "Life." The world admires "Sai Takers," but "Original Takers" are careful to keep their identities secret.

A young man finds and returns a lost wallet and cell phone to a beautiful young lady, thus begins the destined relationship between two strangers. Sound typical? Well then, how about making the young lady the young mans future homeroom teacher, and give them both a twisted sense of right and wrong. And just for kicks, lets have the young man help himself to a self proclaimed reward from the lost wallet before returning it...but of course, this scenario would not be complete unless the young lady was very unforgiving when it came to teaching one of her students a lesson on morals.