Sorry for my intrusion, but what prevents an elf from using a smartphone? Bulma used science to find a dragon that would grant her three wishes. Goku is an alien, Kami-sama is a god. Do you agree with me?
Well this was more about the dev saying it could be a fantasy setting. And sure you can have modern tech in fantasy-ish settings, but if you're going fantasy you might as well have magic stuff.
