Hi Thomas,
In general, a 7 day rail pass is worth it if you do 1 return trip to Kyoto/Osaka, but a 14 day requires a little more travel to make it worthwhile. That said, a 14 day rail pass will cover you from the 21st to the 4th, so lets look at the per ticket costs as shown on the hyperdia travel planning website:
- Narita airport terminal 1 > Tokyo: ¥3140, (62mins, 79km)
- Tokyo > Osaka: ¥13950, (194mins, 556km)
- Osaka > Kyoto: ¥540, (29mins, 42km)
- Kyoto > Kobe: ¥540, (29mins, 42km)
- Kobe > Osaka: ¥540, (29mins, 42km)
- Osaka > Tokyo: ¥13950, (194mins, 556km)
TOTAL: ¥32660 for 6 legs
As you can see, buying individual tickets turns out to be ¥12,440 cheaper than a 14 day rail pass (¥45,100) for this itinerary.
Alternative options?
If you can possibly reduce your time in Osaka to fit within 7 days, a 7 day rail pass would start to be cost effective, but this may not fit with your plans. Alternatively, I would recommend a 14 day rail pass if you included extra trips from Osaka. For example, return day trips to the popular destinations of Hiroshima or Takayama:
- Narita airport terminal 1 > Tokyo: ¥3140, (62mins, 79km)
- Tokyo > Osaka: ¥13950, (194mins, 556km)
- Osaka > Kyoto: ¥540, (29mins, 42km)
- Kyoto > Kobe: ¥540, (29mins, 42km)
- Kobe > Osaka: ¥540, (29mins, 42km)
- Osaka > Hiroshima: ¥10150, (103mins, 345km)
- Hiroshima > Osaka: ¥10820, (109mins, 345km)
- Osaka > Takayama: ¥10610, (223mins, 357km)
- Takayama > Osaka: ¥10610, (220mins, 357km)
- Osaka > Tokyo: ¥13950, (194mins, 556km)
TOTAL: ¥74850 for 10 legs
Adding either of these destinations to your itinerary would add ¥21,000 of ticket costs to your itinerary and make a 14 day rail pass very worthwhile.
Hope this helps!