If you love Ji Chang Wook after his acting in Healer or K2, AND if you don't like the flying/jumping-silly-with cartoonish overlays- type of rom-coms, i DON'T advice you to watch this one.
If you don't already know JCW and like rom-coms, give it a try.
However, if you can get past the first three episodes, the rest is quite fun and enjoyable!
Review of Backstreet Rookie
