He is the heir of this zaibatsu.
Tofugu will reign over the business world in Japan as a zaibatsu sooner or later.
In Japan, there were several financial cliques prior to World War II, including Mitsui Zaibatsu, Mitsubishi Zaibatsu, Sumitomo Zaibatsu and Yasuda Zaibatsu.
A wealth clan is a group of people who do whatever they can to get their money. These are the plutocrats of the world, but you can also call them financial clique or even the Zaibatsu (sometimes brought up in English language history / economic books regarding Japan).
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.