KANJI GUIDE
The sky, and heaven with it. 天国 is paradise; 天気 is the weather.
Half of 瑠璃, the deep blue stone. On its own it is used mostly for its sound and its colour.
A leaf. 言葉, the word for language, is literally leaves of speech.
The orchid. One of the four plants of classical painting, standing for quiet nobility.
The sky, and also empty. Buddhism uses the same character for emptiness — 空, śūnyatā.
The character in 武士道, the way of the samurai, and in 柔道. Read dō, and the head of it is taken for do.