F

F  (エフ, Efu) is a member of Wammy's House, who appears only in the film L: Change the WorLd.

Plot
In Bangnum, Thailand, F discovers Americans investigating a Thai Village, where a deadly disease has been found. While also researching the disease, F comes across a young Thai boy in the abandoned remains of a temple, writing numbers on the temple wall. F shouts at the boy to get out of the village, when they view a U.S. bomber leaving the Village without the Thai people. The Thai people were killed by the U.S. Bomber, because the people in the Thai Village were infected.

After the Thai Village is destroyed, a U.S. Soldier finds a truck moving north in the jungle of Thailand, so the U.S. Commander orders a U.S. Soldier to destroy the truck without any witnesses or survivors. F, driving the truck, manages to escape from the Thai Village with Near. However, they are soon followed by a U.S. helicopter with combat guns. F drops Near off, and tells him to find a phone and call "010-5928-1472-18" and say "F1225" to contact Watari for protection.

He gives a blue necklace (with a chip inside) to the Thai boy and tells him "Good luck!" F is caught by the U.S. helicopter, and he stops the truck and surrenders. The U.S. helicopter shoots at the truck and it is destroyed, along with F.

Before being killed, it is revealed that F had slowly contracted that deadly virus himself, implying that he was already going to die.