As far as I know, nothing. No Japanese words start with "n" - the syllable 'n', not the letter - not to mention this word or sentence isn't spelled in any romanization system I recognise. 'di' only exists in katakana, 's' doesn't exist as a syllable, and 'we' has been obsolete since 1946.
Perhaps you heard it wrong?
Deniva does not mean anything in Japanese.
"Olga" is not a Japanese word or name, so it doesn't mean anything at all in Japanese. Did you mean, "What is the name "Olga" translated to in Japanese?"
The name 'Collin' does not mean anything in Japanese, but it can be written in Japanese as: コリン
Kaitlyn does not mean anything in Japanese, but can be written in Japanese as: ケイトリン
This does not mean anything in Japanese.
what does it mean in English and I'll find out what it means in Japanese for you
Krystle does not mean anything in Japanese, but can be written: クリスタル
It does not mean anything in Japanese, but can be written: マーラナ
It does not mean anything in Japanese, but it can be written: ビンセント
The name Savannah does not mean anything in Japanese, but it can be written as: サバナ
Symantha/Samantha does not mean anything in Japanese, but can be written: サマンサー
The name Carlos does not mean anything in Japanese, but can be written: カーロス