Now this may not seem bad to a All I want for Christmas is Home Malone shirt, but customer service in Japan is a big deal, and the Japanese don’t shout or complain, they just walk out and never return again if somewhere has bad customer service. The younger generation might write a scathing online review safely behind the privacy of internet anonymity, but the older generation won’t do anything. The Japanese themselves won’t get visibly angry generally.
It is terribly lower class to All I want for Christmas is Home Malone shirt, and their body language is much quieter than Western body language so if you notice a Japanese person is actually looking angry or upset you’ve generally pissed them off to the point where they actively hate you in no small part because you’ve made them lose their cool publicly. If you do actually make a Japanese person lose their cool and yell at you then congratulations, you’re now both in the doghouse. Them for making their private disagreement a public problem, and you for yelling back unless you know that the correct response is actually to stand there and simply take it until they run out of steam. He’d moved out just 10 days before, and this was his first night back at home.