Aren't they both vocaloids yet Miku called Luka "human" in the first page?
?_?
Probably because it's an alternate universe where Luka is a song writer and Miku is still a vocaloid.
Anyway, this version of Miku and Luka's relationship always makes me feel good. If only there was a conclusion to the problem at hand, but I'm content with what was given.