JR Pass or reginal pass?

It will depend on the amount of days that you travel. Likely a 7 day Japan Rail Pass is the best option.

Kind regards,
Daniel

Hi Daniel,
Thank you for your reply. Since we're arriving in Haneda on March 22, here is our itinerary:
Tokyo - March 23-27
Disney MiraCosta Tokyo - Mar. 27-30
Osaka - March 30-April 2 ( want to do Kita and Minami districts including Osaka Castle, Dotonbori, Shinsekai,
Nagano (Takayama) - April 2 -4 in Yamanouchi closer to Jigokudani Park to see the snow monkeys. Need to get to Yudanaka station where our hotel shuttle will pick us up.
Back to Tokyo for departure -April 10-11

How many days JR pass should I purchase? Shouold I puirchase the 14 or 21? Will JR pass cover the Osaka to Nagano trip?
Do we need the whole Japan rail pass if we're touring Tokyo for the first week and then Osaka and Nagano for the rest of our trip.
We leave in 25 days. I haven't purchased our JR passes yet but will do it today and so I appreciate a speedy response. Tahnk you so much.

Hi again :)

Apologies for the delay!

If I got this correct, you plan to travel:
30 March Tokyo - Osaka
2 April Osaka- Takayama
2-4 April Takayama - Nagano (for Yamanouchi)
10 April Nagano - Tokyo

Based on this, your best value option would be to take a 7-day JR Pass and use it for March 30th - April 5th + buy a single one way ticket back to Tokyo.

Kind regards,
Daniel