Jamie Joseph plays bizarre Japanese version of rock-paper-scissors involving mallet and helmet

While Japan have made it clear they are looking to make a deep run at this year's Rugby World Cup, that doesn't mean there isn't time for the odd game or two with their coach.

Ex-pat Kiwi Jamie Joseph took time out with his Brave Blossoms for a bit of fun and team bonding ahead of their first quarter-finals appearance on Sunday to play hooker Shota Horie in a game of rock-paper-scissors in front of the rest of the squad.

Although, like many games in Japan, there was a quirky twist to it.

Joseph and Horie were seated with a table in between them which had a helmet and toy mallet on it. The objective of the game was to play rock-paper-scissors with the winner of the exchange grabbing the mallet while the loser grabs the helmet.

The winner then tries to whack the loser on the head with the hammer but if the loser has put the helmet on before then, they're safe and the game resets. If it's a direct hit, the game appears to be over.

Horie got a first attempt and bopping Joseph's skull but the former All Black was too quick. The second round went to Joseph but he too was slow too, although he tried to speed up the play by throwing the hammer at Horie's head. The move got a big laugh from the audience of players.

Finally, in the third round, Horie managed to come away with the win as he landed a clean blow on Joseph. The hooker paraded his win while Joseph looked to make a quick exit.

Japan play South Africa on Sunday at 11:15pm NZT in the final quarter-final of this year's World Cup.