Me and my husband are looking at travelling to Tokyo when your daughter is about 3/4 years old. I have looked on JR east website and cant see how much (if anything) it costs for an under 6 year old, we only use the local above ground lines. There prices for children start at 6 years but no info on children under that age. Last time we travelled to Tokyo it was just the two of us, very different now we have one in tow!
Any help will be most appreciated.