In general the Japan Rail Passes have 3 main benefits:
- Put a cap on JR travel costs (¥28,300, ¥45,100 & ¥57,700 for 7, 14 & 21 day options respectively)
- Give you freedom to change your plans within Japan at any time.
- Ease of use - no fussing with tickets and so on. simply walk on to trains as needed.
WIthout knowing your full itinerary it is hard to give you an idea of whether economically it is the correct choice. Here is some food for thought:
Japan Rail Pass per day costs
If you split out the costs of the rail passes on a daily basis, they get cheaper as they get longer, but these savings per day get gradually less:
- 7 day pass = ¥4042/day
- 14 day pass = ¥3221/day
- 21 day pass = ¥2747/day
Of couse, in reality your trip will be made up of expensive trips and cheaper trips, and so the price per day should be taken with a pinch of salt.
Rough itinerary costs
Based on your rough itinerary for the 10 day period, here are your savings:
Tokyo > Otsuki: ¥2860, (85mins, 87km)
Otsuki > Yokohama: ¥2260, (83mins, 84km)
Yokohama > Kyoto: ¥12390, (164mins, 492km)
Kyoto > Takamatsu(kagawa): ¥9000, (133mins, 291km)
Takamatsu(kagawa) > Hiroshima: ¥7530, (115mins, 233km)
Hiroshima > Tokyo: ¥18250, (292mins, 894km)
JR ticket cost: ¥52290 for 6 legs
- 14 day rail pass (¥45,100) saving: ¥7190
As you can see, even with this skeleton itinerary you will save around ¥7190 over standard JR tickets with a 14 day pass. As a 21 day pass is ¥57,700, you'll need to spend a further ¥5410 on JR travel for a 21 day pass to be cost effective.
14 day vs 21 day
You need to spend a further ¥12,600 on JR travel over the above itinerary for the savings with a 21 day pass to be the same as those that you'd make with the 14 day option. Taking the return to Narita airport costs of ¥5480 out, this will leave you with a minimum target of ¥7120 of travel to do over the remaning 11 day period in Tokyo or ¥647/day.
This cost would certainly be met in one go with a day trip to Nikko, but you can also make good use of the JR Pass in Tokyo.
JR Pass restrictions
The main restriction that you will need to bear in mind as a group is that you are unable to use the Nozomi class shinkansen bullet trains. There are always alternative Hikari class bullet trains that travel on the same lines and to the same destinations which run a little slower that are valid with the JR Pass. These will also be the cheaper fare which will suit your travel companion.
I'm afraid that as the JR Pass is already a heavily discounted ticket there are no discounts available for ober 65 year olds.
The skeleton itinerary I used for your cost analysis is really just the basics based on what you mentioned - your real savings could be much more. Once you are certain of your itinerary I recommend you look up precise train timetables and costs at the Hyperdia travel planning website. You can learn how to use Hyperdia for JR Pass holders through our video blog.
Hope this helps!