This is dependent on the kanji used in the name. There are many possibilities (though some more common than others).
The name "Mamoru" can, depending on the Kanji, carry this meaning.
Mamoru Iga has written: 'Japanese egoism' -- subject(s): Civilization, Education, Egoism, History, Japanese National characteristics, National characteristics, Japanese
karara wo mamoru
守る (mamoru) is the verb meaning "to protect" in Japanese.
Mamoru (his name in the original Japanese) first appears in episode 1.
"Mamoru" means "to protect" or "to defend."
守る (mamoru) is the Japanese word meaning, "to protect".
"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 verb 'to defend' is 'mamoru'. まもる
擁護者 Yōgo-sha
In the last act of the Japanese manga, a naked Usagi and Mamoru are shown waking up in the same bed, and are later shown marrying. Usagi tells Mamoru that she can feel their future daughter (Chibiusa) growing inside her, implying she and Mamoru not only shared a bed, but also had sex. In an earlier chapter, however, there is an implication that she may have had sex with Mamoru
The name Michelle does not mean anything in Japanese, but can be written: ミシェル