Not sure if 7 or 14 days neither 7 and which days

Hi there :)

Firstly, lets get a handle on the full costs of your route in normal JR tickets. A 7 day rail pass is ¥28,300 and a 14 day is ¥45,100 do you'll need to spend more than these to make each pass worthwhile:

1. Tokyo > Odawara: ¥3640, (35mins, 83km)
2. Odawara > Nagiso: ¥10680, (224mins, 381km)
3. Nagiso > Takayama: ¥7230, (243mins, 265km)
4. Takayama > Kanazawa: ¥4180, (186mins, 148km)
5. Kanazawa > Hiroshima: ¥15250, (265mins, 605km)
6. Hiroshima > Kyoto: ¥10790, (126mins, 380km)
7. Kyoto > Tokyo: ¥13220, (161mins, 513km)

TOTAL: ¥64990 for 7 legs

As you an see, both 7 and 14 day JR Passes will offer good savings over standard tickets. As the first day of expensive travel is Day 5, the only way you could squeeze your travel into a 7 day is if you reduced your time in Kyoto (or perhaps took some destinations out?) to leave back to Tokyo on Day 11. I'd personally opt for the 14 day to enjoy the stops out of Tokyo at a relaxed pace - you would also be able to include the return trip to the Airports in the JR Pass (¥5000 if Narita on the Narita Express), however is very much down to personal taste!

Hope this helps!