From top: samurai 士, cover 冖, sitting person 匕. Here: See the cover 冖 as "one" and the sitting person 匕 of a variation of "two"- (The numbers: 1,2,3,10 are: 壱,弐,参,拾)
Mnemonic
In a contract a samurai shall not falsify a "1" to a "2": Thus you need this "one".
The Radical sajinohi means "spoon". But due to its appearance is typically used as a "sitting person". In few cases however, it is understood as claws (i.e. of a bear).
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