Ken'ichi Matsuyama reprises his role as L Lawliet from the previous Death Note films. The film chronicles the final 23 days of L's life, as he solves one final case involving a bioterrorist group that aims to wipe out much of humanity with a virus with ten times the infectiousness of Ebola, taking a boy, the sole survivor of its use in a village in Thailand, and a junior high schooler named Maki Nikaido under his wing.

Shunji Fujimura also reprises his role as Watari, though he dies early in the film as per the events of The Last Name. The characters Misa Amane, death god Ryuk, and Light Yagami also all have brief cameos in the film.

"Have you ever seen fish cry?"

When special agent Ryu of South Korea's secret service fails to prevent the death of an arms smuggler-turned-informant, he instinctively suspects the involvement of Hee, an enigmatic sniper from a North Korean terrorist group.

A skilled master of disguise, Hee has previously assassinated many government officials but since managed to disappear, escaping the unrelenting pursuit of South Korean agents.

Now it appears that she has returned...