L: Change the World (2008)

Blurb:
The legendary detective "L" takes on the "Kira" case in which countless criminals are dying under mysterious circumstances. L successfully solves the case and stops Kira, but only after sacrificing his life, leaving himself with only 23 days left to live.

For his final case L goes up against a bio-terrorist group trying to wipe out humanity with a deadly virus ten times more fatal than Ebola. As L tries to formulate an antidote with a scientist, he must also save the lives of two children who have no one else to turn to.

Source: www.anisearch.com/movie/4473