Oki Matsumoto, chief executive officer of Monex Group

Oki Matsumoto, chief executive officer of Monex Group

Robert Gilhooly/Bloomberg

Monex Group Inc. Chief Executive Officer Oki Matsumoto holds regular parties at the Tokyo-based company where employees must speak globish, or global English, a language for non-native speakers using basic grammar and a vocabulary of 1,500 words.