The most satisfying part of this chapter is that the bartender didn't ask for a tip, even after all that showmanship. He already got ripped off in the end, anyway.
As someone else replied, they don't tip in Japan. Not only that it is considered RUDE, but as a gaijin you'll get forgiven for a lot that a native would not (or so I've heard). I also heard that Japanese-Americans can be treated harshly until it is realized they are foreigners.
Tipping in Japan: Is it rude to leave a tip?
Why is tipping rude in Japan?
In Japan, exceptional service is considered a part of the job, and employees take great pride in their work. You should not tip regardless of whether you're dining at a high-end restaurant in Tokyo or taking a taxi in Kyoto. Instead, Japanese service culture emphasizes hospitality, known as "Omotenashi," which ensures customers receive the best service possible without the expectation of additional compensation.
A Guide to Tipping in Japan
Travelers from the United States and Canada may be used to tipping service workers but in Japan, leaving a tip inappropriately is almost like saying: "This business probably isn't doing well enough to pay you a proper salary, so here's a little something extra." Although there are exceptions, tipping generally isn't a part of many cultures throughout Asia, and in Japan, it's the most taboo.
In some circumstances, the staff will accept your tip with a nervous smile in order to save face and avoid confrontation, or you will have an uncomfortable interaction while they return your money. It's also possible they may not be able to speak enough English to explain why they are returning your money.
Tipping in Japan without a good reason, or doing it the wrong way, could come across as crass or rude and there are only a few times when a tip might be appropriate.