The most common and most likely answer to this crossword clue is the 8 letter word ZAIBATSU
Z
A
I
B
A
T
S
U
Buddy explains!
The straight part
We know that "ig business in Japan" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case ig business in japan = zaibatsu.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does ZAIBATSU mean?
ZAIBATSU noun- A Japanese ‘money clique’ or conglomerate; (by extension) in the United States, any large corporation.