Ryu is a skilled young writer who has a girlfriend, Pin, who hes dated since high school. They love each other and plan to marry. But perhaps because of Ryus fate, he loses her forever in a car accident.　　Ryu blames himself. He withdraws and starts leaning on alcohol. With the arrival of Arm, the grandson of the owner of the company where Ryu works, and their gradual relationship, Ryus world begins to brighten again. When Ryu finds out that he has cancer and may not have long to live, Arm goes all in caring for him and the two decide to live together.　　However, the world is always cruel. When Arm and Ryu learn the truth of something that tears them apart, Ryu disappears from Arms life. Arm tries every means to find Ryu without any luck, until finally, Arm gets a box. This box contains all the answers.