唯一無二

Etymology
From, literally, "only one, no two". Compare Chinese.

Pronunciation

 * いいつ・に [yúꜜ​ì íꜜtsùmù​nì] (Atamadaka + Atamadaka – [1] + [1])

Adjective

 * 1) one and only; unparalleled; matchless; without equal