Amazon Japan has started taking orders for the Nintendo Labo Variety Kit, Robot Kit, and Deco Sticker set.
All pre-orders will ship on April 20, 2018 and everything is eligible for international shipping. Keep in mind the game can be played in English and other languages. Purchase links can be found below.
Nintendo Labo Masking Tapes (exclusive to Japan)
You can also pre-order Nintendo Labo from Amazon US.