one's own

someone's current personal craze or obsession

Doing something at one's own personal pace or speed (unaffected by the pacing of peers).

number plate, license plate

number one

sudoku

(idiomatic) A piece of cake; an extremely simple thing, something trivial, a cinch, easy as pie.

朝飯前: A piece of cake; an extremely simple thing.

(telephony) a common Japanese telephone greeting: hello; used when answering the telephone / used to confirm that the person being addressed is listening, or to confirm if anyone is listening

put away