Reading: JI, ZU, koto
Originally, this character showed a hand holding a flag or a sign aloft.
It's meaning was a place/form of work, such as a guild or a trade (think of a striped barber's pole).
Over time, the style changed to the one shown, but the meaning of work/matter remained.
The current character is a collection of radicals. From top to bottom they are: Ten, box and hand.
Mnemonic: HANDLING TEN BOXES WITH ONE HAND IS NO SMALL MATTER.
(Based upon Henshall, 1998)