Last names?

[Pokemon Master Derrville]

When Ash first goes to challenge for the Cascade badge the sisters are only called the Cerulean sisters, right? Been so long I cant remember. But if so then I guess you can make a argument, even if its a small one, that Misty's last name is Cerulean.

 

[rippedupmemories]

I know a few last names of characters... Gary Oak, Samuel Oak, Ask Kechum, Tracey Sketchit, and Todd Snap. I think last names really ain't that important.