KANJI GUIDE
Both kana for this sound — な and ナ — were made from 奈. And Japan has written foreign names with it for centuries: 加奈陀 is Canada. Yours is in good company.
The only one. 唯一 is unique; 唯我独尊 is standing alone above all.
The capital, and any big city. 東京都 is the Tokyo Metropolis; 都合 is how your circumstances stand.