Will I have any trouble with the locals

Will I have any troubles with the locals in japan being a big guy? I'm 6.6ft or 2m tall and around 400lb or 181kg. I've been watching youtube videos and reading about what to do and what not to in Japan, but I've not found any thing detailing reactions to a big ape like me.

I don't care about rude comments I've heard them all before, and I understand what is considered rude here in the states may not be considered rude else where.

Also police to they tend to give foreigners any grief? I plan to keep my papers on me at all times just in case, but I would like to know if I need to go out of my way to avoid them or not.

Don't be paranoid. Have a good time.

The police don't look for foreigners and single them out. The only times I've dealt with the police were at Koban, either asking for directions or asking if they can find a clinic nearby.

If you aren't doing anything obviously wrong, they won't even look at you. I'm a portly guy, 6' and 275, and no one batted an eye. Make eye contact with kids on a train and smile and say "ohayou" or something and the kids will have a good time. It's a great way to break the ice. Some people will think you're there for sumo training, based on the description you give.

But really, you have nothing to worry about, except where your physical size may pose a problem, i.e. narrow stairs at Animate or other stores, etc. Don't worry about it.

You will stand out, but that generally won't be a problem. Most of the times, you will benefit from your height.

When I was in Takayama during the festival, the foreigners were so easy to spot.

Police never gave me any trouble. They were always friendly and tried their best to help me, even when asking something in English or very broken Japanese. They never approached me, only I them. And was never asked for papers once. But do carry your papers with you, as it is the law.

However, in the states, I would avoid police like the plague

You should have few if any troubles in Japan with the police because of your height or size. To be truthful - I don't actually think the police actually do that much in Japan - but I'm probably wrong on this one.
It's true that people may stare at you - but I find that the Japanese people are used to individualities so most people might stare but would never say anything. I recently noticed that one of the Japan East Train Food attendants was a male dressed in the female uniform with long hair and makeup. If this person does not get stared at a lot - you should also be fine most of the time.
Note that you may have some trouble with the size of Shinkansen and other train seats but it should not really be much of a problem.

Are the seats bigger in first class on the trains? i plan to buy a 21 day JAPAN RAIL PASS: Green to give me access to first class on the trains.

The seats on the first class train I think are normally bigger. They definitely have more leg room which should be handy for your height. It's not that more expensive anyway - apart from people who live in Japan such as myself where it add's up very quickly. Note that you can still catch normal Shinkansen and normal trains even if there are no seats available in the Green Car (but this is rare)

As a 192cm tall 93kg I`ve never had problems with space on the trains. My legs are really long and generally cause problems on all public transport but on the Shinkansen I have a lot of space before the seat in front of me even in normal seats. The local trains can be a bit cramped if you`re sitting but if you`re standing, it`ll be fine.

Yes, normal class shinkansen seats have a lot of legroom. Miles more than first class seats in the UK, for instance.

I'm 6ft 2 and can easily sit in normal shinkansen seats with enough room to put a small wheelie case in between me and the seat in front.

You are a strong man and I hope you enjoy your trip to Japan. Police in Japan are not like police in America, you won�ft have any problem with them unless you do something wrong, they are there to help the people and also the foreigner if you get lost or anyway.

Beside you being tall and overweight it�fs not a problem; you just need to make a few adjustments when you�fre traveling in my opinion. I�fm not going to go into too much detail about what you�fre going to run into as others pointed it out.

If you are a little worried about yourself just do what I did, try to stay away from the metro train or train stations during rush hours and when school kids are going to and coming from school. The train does get pack depending of what time, location, and which train cart you�fre in, you may be doing a lot of standing during the rush hours. Try to take the train cart at the end. Most people normally focus at the center and all those get very full.

Yes you will get look at a lot, maybe because of other reasons but just let it go and smile. Don�ft have that mean foreigner look. I�fm a black guy and depending on what city I was in, in Japan I got look at a lot I found it funny at first.

Again, like I said, if you�fre worried about that one problem, adjust your travel time to the hours stay later where your sightseeing or try to leave early to move onto your next destination to start it at the start of rush hour so when you�fre done there rush over is ending.

Oh yeah, you said "I don't care about rude comments I've heard them all before" all you can do is smile. If i was out there during the time your out there, i would be happy to travel with you.

Have a good trip.