This story is interesting in a couple of ways. One is how some gender stereotypes are flipped with regard to San and Ashitaka's roles in their romance. San essentially proposes marriage in her clan's form of it (I fail to see the difference between marriage and taking mates except one being wolfy), and he has to then accept it. Ashitaka takes the tradtionally feminine role in pining after her while still trying to be responible.
Another thing that's interesting is San's identification with the wolf species over her genetic human form. As with the film, San insists she's a wolf despite her obvious human body. Taking it a step farther than the flim, everyone around her tries to convince her she's really human. That is, until Ashitaka's little sister Kaya gets there and is able to recognize San as a wolf because of her demeanor, and she thereafter refers to her as a Wolf God. San's wolf status is her identification with her adoptive family, and its real world equivalent would be someone adopted by a family of another race or country who prefers to be considered a part of their adopted family's culture. As a transgender girl, I can relate to it on the level where San is human in body but wolf in spirit and prefers to be seen by her spirit.
Kaya blinked, not sure she heard right. "My brother married a wolf?"
She was stunned, to say the least- was her brother a pervert? 'Mating' with a wolf- what would their mother think? Were there no humans he could love?Tee hee.
Overall, though, this fanfic is sloppy. It has difficulty with characterization all around, but mostly of San and Ashitaka and ends up making these soft-spoken respectful warriors of ancient Japan into modern teenagers worrying about their relationship. The first part with San talking to her brother feels like what the author would say to her to make her accept that she likes Ashitaka. Meanwhile, Ashitaka plays "she's not my girlfriend; no, she totally is!" with the Forest Spirit. If you were visited by the spirit of nature, would you talk to him about your relationship concerns? Really? At one point, Toki talks with San about boys, and that is the only discussion about romance that makes sense. Toki is that kind of person, while the gods of the forest certainly aren't. Maybe that could work in a Buffy the Vampire Slayer fanfic, but on Buffy, they're trying to poke fun at both fantasy pretention and modern American lackadaisical teenagers (i.e. not something that would work in Princess Mononoke).
In general, its problem is that there's too much talking. Princess Mononoke is a subtle Miyazaki movie. Its strength is in its atmosphere, not exposition. Though there is some important dialog, such as when Lady Eboshi shows Ashitaka her secrets, the words are very deliberate. "Show, don't tell" is the storyteller's mantra, something that Desaix did not take to heart in this fanfic's creation. A lot of the story developments I could accept if they were presented through showing and not telling.
The plot itself has the Forest Spirit's ghost playing Obi-Wan to gather the main characters and prepare them for a journey. The journey itself seems mundane in its purpose, but I imagine more interesting things would come up if the story was to continue. One thing that strikes me as odd is that Lady Eboshi would come on the journey without a significant entourage--she is the ruler of Iron Town and involved in a hostile political struggle. At least, I'd give her some bodyguards more fearsome than Toki and Koroku.
I also dislike Desaix's decision to have the Forest Spirit give Ashitaka the strength of the curse with none of its drawbacks. The point of the curse was not to give Ashitaka a really cool weapon, but to give physical form to hatred. Hatred turns gods into mindless demons, and the hatred spread from the demonic Nago's touch would kill Ashitaka even as it made him strong. The Forest Spirit healing him is part of a message of hope where he forgives everyone and encourages them to get along. The characters have their own weapons to protect them, like arrows and knives, and they don't need the otherworldly hatred manifestation.
To sum up, it presents some interesting ideas but isn't written terribly well. The story is told more than it is shown and isn't true enough to the source material. It's nice to read once, but I think I'll be bumping it off the favorites list.