[Sangetsu]

In Japan, standing out is not encouraged. Your tattoos and piercings will be noticed, though very few will react visibly or audibly to them (unless you are applying for a job).

Discrimination exists in Japan. There are places (bars, hotels, clubs) in Japan which allow "Japanese" only. This is an obvious form of discrimination which is technically illegal, but that hasn't stopped businesses from putting out "Japanese Only' signs next to their doors. The less obvious forms of discrimination you will never notice. Manners are a fine art in Japan, and many foreigners are not treated with the same respect as Japanese are. Being treated in such a way would be insulting to Japanese, but most foreigners would never be aware that they were treated any differently, or that they had been insulted.

Your tattoos and piercings pretty much put you out of the market for the majority of jobs which foreigners work in Japan (teaching, finance, IT, etc.), but you would probably find ready work at a bar or night club. Working at a trade will require a fair amount of Japanese ability, both spoken and written.

Your online degree will probably be enough to get you a work visa, provided it is from an accredited university. There are a few online universities which are not recognized as accredited, University of Phoenix being an example.

The cost of living varies greatly in Japan. And where you live in Japan depends primarily on your job. If you aren't working as a teacher, most likely you'll be working in one of the larger metro areas, which can be quite expensive. But it's not all that bad. An apartment can be expensive (and cost a lot of money to get into), but there are many people looking to share large apartments and houses, and the rent for a single room is usually very reasonable.

As for living in Japan, it's all a matter of opinion. Personally, I think Japan is a wonderful place to visit. On the other hand, there is nothing terribly special about living here.