An art made of material fir and maple grown in Hokkaido. Roll a ball from the top of the xylophone and enjoy the tone.
You can find a vending machine placed at the top the xylophone and purchase a ball cost you 300 JPY for one. Play with the ball as many times you want and bring it back home as a souvenir. Do not forget the ball next time you come back to play with xylophone.