Long before the anime, before the brackets and the bracket-ed brackets, a Takara designer named Takafumi Adachi was reading Beigoma — an Edo-period spinning top wound with string and slammed onto an inverted rice bowl. He kept the slam. He kept the bowl. He swapped the string for a ripcord, the iron for ABS plastic, and screwed a bit-chip into the head so kids could collect the souls.
The product launched in July 1999 in twenty-three Japanese cities. By December the manga had begun, by spring the anime, and by 2002 a generation of children on five continents could pronounce fusion wheel before they could spell multiplication.