No idea. They are proper S15 mats afaik. I have a full set in my car and this is a spare front. My friend has totally different silvia branded mats in his S15.
I can check shipping tomorrow. You are Japan based?
That's the company just send them an email with what you are after an they should be able to help.
I have the part numbers somewhere for the bits too so I will see if I can find them