This cute little movie is silly and it's fun.
It reminded me a lot of the excellent "Scott Pilgrim Vs The World" since the tone is very similar : fill your story with crazy, funny stuff and pretty, sexy young actors while maintaining a solid emotional core capable of touching the heart.
The first ten or so minutes set the scene, with the sister's names a major tip-off as to director Shaun Su's strategy, as well as one of them being a fan of bows and arrows. The periodic violence is cartoony and no blood is shed.
Like I said : silly !
If you like SPVTW, do yourself a favour.