We may have some spare time at the end - basically we wake up in Hiroshima on a Tuesday morning (in a few weeks, August) and are flying out of Narita @ 4pm Wednesday. So we have 1.5 days and all we need to do is take the train up to Tokyo and out to Narita, which should be ~6 hours or so.
We'll be taking the train throughout our trip. Thoughts on places we could stop along the way between Hiroshima and Tokyo? It would need to be something along that train line for a ~half-day outing.