Activation in Fukushima

I will arrive in Japan by Tokyo and from there go to Fukushima, but i want to activate the running days when i am at Fukushima only, because i wanna use from determinate day until the rest of my trip, is it possible to activate the begining of the days from Fukushima or when i arrive at Narita i go to the activation place and ask them to make it start only some days later?