What does this "Nishi" part means? Do japanese names mean something? Kazakh names do (though I cannot say what my name mean, it's not clearly Kazakh, just partly, it was made of kazakh word "danalyk" which mean "wisdom", so "dana" in names means something like "wise"
"Nishi" in Kei's surname and Nishioka's surname are different.
In fact, Kei's surname is quite an uncommon one. It's written as 錦織 in kanji characters, and this surname is usually pronounced "Nishiki-ori," the first kanji 錦 is "nishiki" and the second one 織 is pronounced "ori."
But in Shimane, where Kei comes from, this surname is pronounced Nishikori.
If you show the name 錦織 to random Japanese people, most of them will say it's pronounced "NISHIKI-ORI."
"Nishi" in Nishioka's surname means "west." "Oka" is "hill." His name is written as 西岡 in Kanji characters. The first one is "Nishi" (west) and the second one is "oka" (hill).
This 西 (Nishi) appears in many surnames, such as Nishimura, Nishino, Nishida, Nishikawa, etc.