Everyone loves a good heist show. See the Italian Job, Ocean’s Eleven, and the Kaitou Kid from Detective Conan, not to mention the numerous novels that the Japanese and French in particular have come up with. What makes 20 Faces’ so disappointing is that it started off being almost the best show of the season, alongside the likes of Kaiba (what the hell happened to it?), but ends up being subpar Hirano Aya chanting "OJIISAN!" every episode.
When you let the likes of Special A beat you, something is terribly wrong.
PS: Hirano Aya really sucks at singing, and French. See episode 16. Ranka’s Nakajima Megumi on the other hand, is better at both acting and singing by a large margin. And that’s an impartial view.