I have watched the anime dteath note and was in love with the series. As I know the main story but will not disclose it because it is good to it yourself, but I can ensure you that you will love the story and the performance. The trailler is interesting too how he uses the death note in different ways.
Both the character in this film are genius and the dialouges are good too( if they are same as the series) .
Overall it will be a good decision to watch this film.
Hope for the best. Thank you.!