If you use a samurai from feudal Japan who is catapulted into the far future, and you want it to be realistic, you will need to do massive amounts of research to get everything correct. It's not simply a matter of reading a couple of books, you'd need to be able to get into the mindset of someone who is born into a wholly different era with a wholly different culture, and you'll have to become an expert on every aspect of his life and times. Only you know if this amount of research is something which would come easily to you or which you would find congenial, but to be frank if this were something you'd enjoy doing I rather think you'd have started the process so you wouldn't need to be asking our opinion on the subject generally.
If you're writing about someone who is born in the future, whether or not on a different planet, then again you need to immerse yourself in a wholly different culture and era, but the advantage is that you control that future and its culture, and if you don't know some aspects of the man's samurai heritage or you get it wrong, it can be glossed as a consequence of that heritage having been altered or diluted over the centuries.
However, I have to ask -- why are you so intent on getting a samurai into your story? Why use something which is so clichéd? Invent your own warrior caste. Work out when and why they arose, and then use different aspects of different cultures and meld them into something which is unique because it's all come from you. That to me would be far more satisfying, and much less problematic.