Vitz hybrid is NOT very popular in Karachi, or Pakistan for that matter. If resale value is your concern then Aqua would be better off.
However, everyday I come across people complaining about their hybrid batteries being faulty.
Since the import of JDM has been made difficult, not many are imported anymore. The ones you might be seeing on the road are probably the older models. Also, the ones that are being sold to you are probably the second-hand cars.
Buying a Pakistani used hybrid is the worst idea imaginable. Sure, a Japanese used car wouldn't be that bad. However, the Pakistani used JDMS are prone to be meter tampered, etc, their color truly shine when they are brought home.
If you have the guts to buy a JDM, be aware that the spare parts are sourced from the junkyard and not the dealership. Broken and stranded in the middle of nowhere? Well, most roadside mechanics can't fix it, they will probably die trying.
I apologize for being seemingly anti-hybrid car person. But I would never consider buying a Pakistani used hybrid. Hybrid cars are a blessing for countries that have backup platforms for them. In Pakistan, you are on your own. Sorry for the long post.