Reminds me a teensy bit of...
Sym-Bionic Titan. Princess from another planet who is cheery, quirky, and friendly, guy who fights with her and sometimes tries to protect her against her wishes. The two main characters made just as cute a potential pairing as Star and Marco do. The problem with Sym-Bionic Titan was the high school stuff was cheesy and taken a bit too seriously. I like that this show is more light-hearted in that area. Also it seems like it's going to last a lot longer.
Anyone else know what I'm talking about?