Usually, I'd like to come up with the character first, and then find a name that fits their description.
I don't suppose you need to learn Japanese to use Japanese names, (if your game isn't japan related or some sort of old-school otome game) but you need to know how people would direct each other in Japanese if it is going to be one of those games that use Japanese references.
Since I took some japanese I can help you there ;v;
A majority of Japanese people have one given name, one surname aka family name aka last name. Though, unlike America or wherever else, they do not have a "middle name".
Usually when you're speaking to someone, it all depends on your relationship with them depending on how you'd address them.
So for example, if you weren't as close to someone you'd refer to them using their family name.
It's also unlikely that Japanese people would ever refer to their elders (like a teacher) by using their name at all. Typically, they'd say something like "sensei,"
If you're close to someone, a boy, for example, you'd address him as, (First name here)-Kun.
If you're close to someone, a girl, for example, you'd address her as, (First name here)-Chan.
In school. . lets say your like a freshman and you are familiar with a Junior. . it would only be but polite to address him/her are senpai.
Usually in the Japanese language they use sama or san to show respect, it's equal to the english, "Mr." or "Mrs."
Anyways, enough with that talk.
If you want Japanese girl names:
http://www.20000-names.com/female_japanese_names.htmIf you want Japanese boy names:
http://www.20000-names.com/male_japanese_names.htmAnd if you want family names:
http://www.rootsweb.ancestry.com/~jpnwgw/Names.htmlHave fun ~ ^^