It's not (close to) a rip off. It's an intentional homage to Japanese film and culture, even more so than the Original Trilogy. Star Wars has always taken inspiration from broad Japanese culture, and so have Lucas and Filoni themselves personally.
I say this as a Japanese person (born in Japan). I don't think there's a specific resemblance to that character, outside of bearing a resemblance to somewhat standard fantasy kunoichi design. It's a bit of a reach that a 1998 PlayStation has influence on Ahsoka of today.
There is no similarity in the name other than starting with an A. Ayame is a Japanese name. Ahsoka is taken from an Indian name. Her name was originally Ashla but Lucas decided to use the name of the Indian Emperor Ashoka, which I find ironic because that's the most common misspelling of her name.
But if you feel there's a connection there and you take something positive from it, then there's nothing wrong with that of course.
I appreciate and love this Ahsoka outfit because it has a lot of rich textures and layers and combines Japanese and Star Wars aesthetics incredibly well. Which is the whole episode, really. I think the tabi are a bit too far, but everything else is perfect.
