Not Saito San, but my experience was that they don't accept calls from abroad. And my Japanese contact tried to call them and never got through... Maybe hotel concierge has more chance.

Thanks for your reply! I actually messaged them via facebook and they accepted my reservation.

@guest This is funny, I contacted them last night via Facebook message and they told me I have to book via hotel concierge again... But glad that you got lucky on this.

Sorry for the late reply but I think that they only accept reservations via facebook from Japanese customers . I actually gave the contact of one of my friends in Japan instead of my own information. (+ I wrote to them in Japanese). They must've thought I was Japanese haha. Maybe next time you should try that instead.

If it's late at night there is a possibility you'll be able to walk in, but since it's a popular restaurant, it's safer to make reservations in advance.