Medium Size Dog Tokyo Traveling

I have scoured the Internet trying to find answers. My dog is medium sized, he is a border collie/lab mix. He does not fit the requirements of the crate to ride on the trains.
Has anyone utilized the pet taxi services or is a medium to large dog owner in Tokyo that can give advice or their story?

It's really putting a lot of stress on us if we want to take him or go through the agony of getting rid of him

Please don't ever "get rid of" your family member only because you are relocating! (Is that the situation?)

Locals who live with a medium to large dog here tend to own a car so that they can drive with them to parks and places on the weekends... is that an option for you?

If you are relocating to Japan with your dog, bicycle is also a transport option. I know, I sound like a crazy person proposing the use of a bicycle for everything and anything but it is actually quite common in Japan including for mid sized dogs. Bigger dogs I guess have to run along

Check it out here:
https://www.google.co.uk/search?q=ママチャリに犬&client=safari&hl=en-gb&prmd=ivsn&source=lnms&tbm=isch&sa=X&ved=0ahUKEwi2j9HdzunVAhUIErwKHZnjA4YQ_AUIECgB&biw=375&bih=603#imgrc=vPRC9WVaWk3AFM:

There are even specific dog baskets for bicycles being sold. And in a country where mother (or fathers) ferry around 2-3 kids on a bicycle, a dog on a bike is not a rare sight.

Enjoy your stay in Japan!

I think you need to elaborate a little more on the situation you're asking about.

Are you moving houses and ...going by train to your new place? So... you need to bring your dog onto the train?

Or are you meaning just moving around the city, say, you want to bring your dog to a dog park but are riding the train to get there?

Another situation?

If it's just a one-time thing, there are plenty of solutions besides the train. You could rent a van, for example, and drive. You could post on a forum and ask if someone else could drive to help you out, for a fee. A vet clinic might have some contacts... I know some shelters or boarding places have relocation/pick-up and drop-off services you could negotiate for. You might even be able to find a taxi that's cool with a pet, if you call and explain ahead of time. If it's a long-distance train, how about flying instead? I'd even call and ask the delivery companies like Sagawa or Kuroneko if they've got any sort of way to handle live animals. I mean, I buy fish on amazon sometimes... I know it isn't the same thing, but surely someone is delivering animals to pet stores, for example?

If it's a frequent thing... there are also plenty of solutions, but they may be different. The bicycle idea is a good one, or just walking. Finding closer places. Finding a friend or renting a vehicle. Talk to your vet, again, for any ideas. Etc. Etc.