What is the storyline of vocaloid?

There are no official fictional stories associated with any of the Vocaloid characters. This is left entirely up to the users and fans to invent their stories through song, animations, drawings, etc. There have been some published comics that tie in many of the Crypton Vocaloids and fan-made derivative characters into an episodic storyline, but this is not official background for the characters. It does help serve as a common baseline for the fans, however, people should not feel restricted to these.

Well, Vocaloid doesn't really have a story line. I mean it's not a manga or anime so, I doubt it has one. Maybe the story line would be then are a computer generated and animated group of singers in Japan. Also just a little extra knowledge. Just because Hatsune Miku has a 01 on her doesn't mean she was created first. Same goes with others Vocaloid's. I think the first was Leon and Lola, and yes they are Vocaloid characters. Hope that helps clear things up! \ ( ^.^ ) /