utensil, thing, ten
什 centers on a concrete object or tool, with a secondary numerical sense of ten that likely arose from its use in counting or grouping items.
什 combines 亻 (person) with 十 (ten), originally referring to a group of ten people or a set of ten items, later extended to mean a utensil or thing.
A person 亻 beside ten 十 items: imagine someone organizing a set of ten utensils or tools.
For ジュウ, picture a person using ten utensils to make juice: juice -> ジュウ, and the ten tools are all needed.
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