The Japanese business world is lubricated by after-hours socializing at karaoke bars and other drinking establishments. Salespeople in particular spend a lot of time (and money) entertaining clients. In most cases, these gatherings are sponsored by companies. Many sales representatives have fat expense accounts.
Of course, not everyone enjoys schmoozing with customers into the wee hours of the evening; but these expense account entertainers are nevertheless the objects of envy among those employees who don’t enjoy the same privileges. They refer to these lavish entertainers as shayōzoku—“the corporate business tribe.”