As far as i know this is not a yaoi anime
Period.
To talk about this anime/manga i was wondering what were the other works of the author and here's what i found in wikipedia:
Tsugumi Ohba (大場つぐみ Ōba Tsugumi) is a manga writer. As Death Note, the author's only work to date, is suspiciously well-written for a debut work, it is suspected that "Tsugumi Ohba" is only a pen-name for a more famous author.
I would say the true author could be the author of Detective Conan regarding the complex plot, what do you think about it?
I've seen a few episode of Conan and i noticed the investigations were very weird, just like what happen in death note.
Thanks God, it's not a Clamp's work, sorry suzaku_nomiko