Nintendo has announced a LAN adapter for Wii U which will let you play the 3DS version of Monster Hunter 3 Ultimate online.
The 3DS version of the game does not have online play built in, unlike its Wii U brother. But by plugging in the Wii U adapter you can trick the console into connecting your 3DS version to Wii U servers for the game.
It's a bodge that makes use of the fact that 3DS players can join in a local Wii U game.
But the adapter requires a Wii U "relay download tool" to be active for it to work - which means you can't use it and play the Wii U version of the game at the same time.
You also can't create a new party on Wii U servers, but you can join Wii U games created by other people.
Confused? Yes. Nintendo of Japan announced the gadget during a 3DS-focused Nintendo Direct conference earlier today - there's no word yet on a European release. The game is set to launch in the UK on 23rd April.