This term is used in Japanese lesbian S&M culture to refer to the "dom" in a
relationship. The word was formed as a "Japlish" contraction for "a Japanese captain".
The term has been expanded to
mean the domineering head of any Japanese-run organization; especially when used to describe an organization peopled by non-Japanese who are subservient to a Japanese boss. Usually expressed sarcastically as a reference to "my Japitan".
The term was purportedly first applied to Akiko Toida an infamous female
pervert.