What does the name yuna mean in Japanese?

"it means "lovely maiden" in Hirogana, and "moon maiden" in Katakana."

First of all, hiragana and katakana are Japanese syllabaries, not languages themselves.

湯女 (yuna) is a noun for "woman who assists bathers at hot-spring resorts; bath house prostitute" in archaic Japanese.

湯 - hot water

女 - woman