TV-MA | | Adventure, Crime, Drama
A high school student named, Light Turner, discovers a mysterious notebook that has the power to kill anyone whose name is written within its pages and launches a secret crusade to rid the world of criminals.
Sleep is key to strong thought.
When Light threatens to write Ryuk's name in the notebook, Ryuk says that no one has written past the second letter in his name. Prior to this conversation Light read a note that said "Do not trust Ryuk, he is not your friend or pet" meaning Light should have known it wouldn't work on him and that someone had gotten past writing Ryuk's name.
Correction - What we saw written was a warning not a notice of death, a Death Note of you will, so maybe there's different rules for that (there is a lot of rules after all) Plus who says Ryuk is his real name.
Near the end of the closing credits, Ryuk can be heard laughing.