You're both wrong, the Mirai uses a fuel cell as the voltage source for an otherwise EV drive train. The Mirai is an EV with a fuel cell instead of a battery.
EVs are so much more cheaper to own that it is difficult to explain to people who own ICE cars as they, in majority of cases, just cannot comprehend it
My EV has cost me ~$1,100/yr less to operate over the last few years for the same mileage compared to my ICE, and I didn't even have any major issues with my ICE. Meanwhile its been charged with almost exclusively 100% renewable, zero-emission energy.