To start with the basics. This is a shonen manga. Its also one of the few shonen manga in which the fight scenes are nto only few in number, but fully comical.
Death Note is about a 17 year old high school genius and a demi-god called a Shinigami. It all starts when 17 year old Raito Yagami is coming home from school one day and finds a black notebook in the road. He takes it home and reads the first page. It says that whomever's name he writes in the book will die of a heart attack within 40 seconds unless written otherwise. Skeptical, he writes down the name of a fugitive who's holding a day care full of kids hostage. The fugitive dies of a heart attack 40 seconds later. When Raito turns around, he finds a demon in his room. I forgot the shinigami's name, but he introduces himself. Raito soon finds himself killing murderers with the note book(death note) under the name Kira, which was given to the unknown killer by a website(Kira is bad romanjii of killer.) But, all is not well. Kira/Raito is dubbed a murderer by the Japanese police and Interpol and the United Nations. They send in the world's greatest detective, a man called L, to find Kira. For a while, this begins a rare struggle between what two people think of as righteous and the hunt beings for the real name of the opposer. Until a young model name Miso enter the scene as a second Kira who can see the name of people just by looking at them. She devotes herself to Raito because he killed the man who killed he parents. This leads to a strange turn of events and eventually, Miso is caught and detained by L and a special section of the police. She herself has a deathnote, by the way. Anyway, Miso gives up her rights to her death note, making her forget about deathnote. Raito tells the police to detain him to prove that he isn't Kira, as he is one of the main suspects. He too gives up possession of his death note, but before he did he had burried it, which leads me to believe he will later reclaim death note, even tho' I haven't gotten there yet. I'm not going to give the rest away.
The characters in this story were extremely original and believable.
This is by far my favorite manga ever. It would, however, really suck as an anime. Any Shelock Holmes and Case Closed fan will be enthralled by this. 5/5 points, beezatches!