Mark had a history with long-running shonen shows. He was still recovering from the thousand-episode commitment of One Piece and the endless fillers of Naruto . He needed to know exactly what he was getting into. He wasn't looking for a casual dip; he wanted to know if he could finish the series over a long weekend.

In addition to the standard episodes, there are two "Director's Cut" compilation films that retell the story with added scenes:

The series follows high school student Light Yagami, who discovers a supernatural notebook that kills anyone whose name is written in it. The 37-episode run is typically broken down as follows:

Focuses on the intense psychological battle of wits between Light (Kira) and the world-renowned detective known as L.

By the time he reached the final episode—Episode 37—he was exhausted but satisfied. The story had a beginning, a middle, and a definitive end. It hadn't overstayed its welcome.

If you're counting recap specials or live-action adaptations, those are separate, but the main anime series is 37 episodes.