way to rework this itinerary for rail pass?

Poor foresight on my part, but I think I may need to buy a 21 day rail pass for a 15 or 16 day itinerary. Does anyone see a work around? It's likely too late to change my accommodations. Rail pass will be needed on 4/25 to go back to Tokyo. The only work-around I see would be staying in Tokyo on 4/11 and not using the pass until 4/12, which would be a bit annoying in terms of having to change hotels and not be in Nagano for 3 nights.

4/11: land in Tokyo and head to Nagano
4/12: Nagano area
4/13: Nagano area
4/14: To Mishima and rental car to Fuji Kawaguichiko
4/15: Fuji
4/16: Fuji
4/17: return car in Mishima and up to Fukushima
4/18: Fukushima
4/19: Fukushima
4/20: up to Morioka
4/21: Morioka
4/22: up to Aomori
4/23: Aomori
4/24: Aomori
4/25:back down to Tokyo
4/26: fly out of Tokyo

hi!

I guess my two big questions are: where in Nagano are you going? and Could you rent the car from Otsuki instead of Mishima?

Are you spend a few days hanging out in Nagano-city or??

Sorry, I think I've asked a few questions recently on this forum so I didn't want to re-post my full itinerary.
I'm going for cherry blossoms and since the season is looking like it will be early this year, I'm between going to the Nagano area or Mt Yoshino for those first 2-3 days of my trip. I have hotels double booked in Nagano and Kyoto. Nagano would be a base for Takada Park, Takato ruins, Matsumoto, and whatever else time allows.

I suppose I could get a rental car from Otsuki but I picked Mishima since it's on the shinkansen line.
I'm not sure what you're trying to get at with Otsuki. Is it so I can base in Tokyo and then head out to Otsuki when I am going to Kawaguichi? Otherwise, I think the local trains would take too long to get there from Nagano.

Do Fuji first and get a car closer to Fuji.

Then do the rest of the itinerary as is.

You could also have a look at flying from Aomori to Tokyo at the end of your trip. This might give you a bit more time to explore sakura sites in the north. It might be a bit late to get the cheaper advance booking tickets though.

I ended up just buying the 21 day pass. Could use it for the N'EX on day 16 as well. It's probably too late in book a flight from Aomori to Tokyo for a reasonable price anyways.