Wow… just wow. There is so much wrong with OP's post, I don't even know where to start. Let me start by saying this:
NEWS FLASH: Being white is NOT going to get you laid. If you cannot get laid in your home country, you cannot get laid here.
Second, knowing about J-pop and Japanese culture WILL also NOT get you laid here. Most ladies don't even care about manga. More importantly, the Japanese culture you learn about in manga isn't REAL Japanese culture. By the way – don't ask me what REAL Japanese culture is because you have to LIVE IT by LIVING here in Japan not by reading a bunch of comic books.
REAL JAPANESE CULTURE is deep and beautiful and you'll probably never understand it because your goal is to have sex with Japanese girls. (You said Jgirl, which is a disrespectful term. Japanese ladies here like to be treated like the princesses they are, and you have to learn to be a gentlemen before you should even consider coming here if you want to get any attention from these angels.)
Next, the Hub is not for you. The Hub is a classy pub frequented by well-adjusted, working people. This is not the place for a person whose career is brushing dogs. You will be laughed out of the Hub for even trying to fit in with us.
As for love hotels, you don't even need to think about it, as you'll never get that far in a relationship, judging from your OP. Same with onsen.
And your 4-inch dick IS NOT big, by the way. I don't know what you've heard, but 4 inches is only slightly above average in Japan. Don't act like you're swinging around an elephant trunk when you're still within one standard deviation of the mean.
Finally, if your goal is to teach English here, you're out of luck. Japanese English schools have high standards, and judging by your post, English wasn't your best subject in high school. You also need charisma and social skills if you want to get hired at an eikaiwa. You act like just anyone can become an English teacher as long as he's white – again your white colonialism bias is leaking through.
My honest advice is to stay in America. I'm going to be sharing your post with my friends at the Hub next weekend, and we'll all be laughing at you. Japan is NOT for people like you.