A

A is mentioned briefly once in the book Death Note: Another Note. A was the original successor to L and lived at the orphanage known as Wammy's House. A committed suicide after the pressure of having to succeed L became too much for him to handle.
 * In the film L: Change the World A's name was not seen on L's computer screen.
 * It is mentioned in one line of the novel that A is male.
 * A may be still alive right now.
 * A's Youtube Channel: www.youtube.com/user/AgentAdam33