College student Hagino lives an ordinary life until the day his upperclassman from high school appears before him. This is Enomoto, a bold man with a mean look in his eyes who was supposed to have died in a terrible accident and whose real body remains in a coma. Enomoto is the best friend of the senior student Hagino has a crush on. Declaring himself an angel, Enomoto delivers a shocking revelation: if he can take the life of his own close friend within 49 days, he can return to life in that friend's place. The very man Enomoto is here to kill is the one Hagino tried to protect when the accident occurred. Enomoto brazenly moves into Hagino's living space, beginning an uneasy cohabitation between an egocentric freeloader and a dog-like landlord. As the 49 days tick down, their tense days together become almost calm and even oddly fun. Hagino starts noticing a charming side to Enomoto, and just as his heart begins to waver, Enomoto steals a kiss from the sleeping Hagino. The story follows this secret enmity that slowly blossoms into something more within their strictly limited time. The narrative is divided into a main story of heavy drama and after stories that are purely lighthearted fluff, creating a notable tonal shift as it explores how their relationship changes and blooms after the climax passes.