That's one of the toughest jobs going – is he a wizened veteran?
Not exactly, Mr Azumi is just 49, which makes him a babe-in-arms by Japanese political standards. He's never held a financial or economic brief before, or even pronounced publicly on such matters.
So isn't this rather a curious appointment?
The gossip in Tokyo is that he was not the first choice of Yoshihiko Noda, who became Prime Minister last week. The other way to look at this is that Mr Noda is a former finance minister himself – he may be planning on keeping a tight grip on such a key department.
What does Mr Azumi say?
He's already signalled tax rises may be necessary to deal with Japan's gaping deficit, but we may get a better idea about his views next week, when he'll attend his first G7 finance ministers meeting in Marseille.
So what's his background?
He's a former journalist – don't mock, it was good enough for George Osborne – who was first elected to Parliament in 1996. Most recently, he's been the Democratic Party's head of Parliamentary Affairs.
And his areas of expertise?
If his website is anything to go by, the work of Exile would be his specialist subject on the Japanese equivalent of Mastermind.
An arcane monetary policy guru?
Not quite – Exile are a 14-member Japanese boy band who have shifted millions of records over the past 10 years. Mr Azumi admits he's a huge fan and says one of his all-time highs was getting to meet some of the lads at a ceremony that marked the anniversary of Emperor Akihito's accession to the throne.
Anything else we should know about this boy band-loving finance minister?
He's married with two children, says he loves the books of Seicho Matsumoto, one of Japan's best-known crime writers, and is partial to a bit of pickled aubergine with curried rice. The rest of the G7 crew might want to stand upwind of him when they meet next week.