A race of immortals have their memories wiped every fifteen years, all relationships that they otherwise had are now gone from memory completely. Other things stay, learned knowledge, personalities themselves. Lavi Bookman has finally caught up with this affliction, after years recording each and every day that passed. Allen Walker remains a constant.

Allen Walker, Age somewhere around 20: Occupation- Batista, Sex: Female Kanda Yuu, Age 23 Occupation- Student. Sex: Male Lavi Bookman, Age 22, Occupation- Putting Allen Walker and Kanda Yuu in the same vicinity as much as humanly possible. One catch, no one can tell just what the hell is in Allen Walker's pants, or just who the hell Allen Walker is.