Who did it first?
Anyone who watches the anime Erin The Beast Player/Kemono No Souja Erin can't deny Okami's heavy inlfuence on the anime in terms of art and presentation but one thing remains a puzzle. There's a striking resemblence in the story of Beast Player Erin and Team Ico's upcoming PS3 exlusive, The Last Guardian.
Both stories revolve around a human becoming attached to an animal of some sort and show the main characters as they interact with each other and overcome the hardships they face together. In addition to that, the design of both creatures is similar and there's a heavy emphasis on the setting and theme in both the videogame and the previously mentioned anime. Do you think it's coincidental?
The Beast Player Erin is an anime based on a novel that has the same title. It's written by Nahoko Uehashi who's best known for the popular novel and TV series Seirei No Moribito. The novel was published in year 2006 while Team Ico's The Last Guardian is yet to be released.
Judgement:
I think it's a pure coincedence. These kind of situations are very common among concept artists to a point that I would call it unavoidable. It's not surprising to spot out major similarities between art works that are done by various artists as chances that you have two people who are thinking of the same idea are high. Not to mention that it's very likely for ideas to be similar when the source of inspiration is one.
I'm a huge fan of Team Ico and a fan of Nahoko Uehashi and I welcome all sorts of good entertainment whether it's original or not. Enjoyment comes first.