The names here are written in the Japanese way, so the last name comes before the first. Stresses are put on the first syllable of each name. (e.g. Mine Sayaka)

Kurogane Yaiba:

Kanji:
Pronunciation: Koo-lo-gah-neh Yah-i-bah
Meaning: Iron (or steel) sword

Kurogane Kenjuurou:

Kanji:
Pronunciation: Koo-lo-gah-neh Ken-joo-lou
Meaning: "Ken" means "sword," "juu" means "ten," and "rou" used to be a common ending for boys' names.

Mine Sayaka:

Kanji/Hiragana:
Pronunciation: Mii-neh Sah-yah-ka
Meaning: "Mine" means "peak," but it can also mean "the back of a sword." "Sayaka" is a normal Japanese name, but it means "clear" or "bright."

Onimaru Takeshi:

Kanji:
Pronuncation: Oh-nii-mah-lu Tah-keh-shi
Meaning: "Oni" means "demon" or "ogre." "Maru" is usually defined as "round" or "circle," but it can mean "full" or "complete." In other words, the name "onimaru" means "complete demon." "Takeshi" is a common Japanese name, but the name means "strong." For some reason, though, the kanji used for "Takeshi" in Onimaru's case is different from what is usually used.