When Tatsufumi Sakai was named chief executive and president of Mizuho Financial Group this year, many bankers and investors were surprised.
The low-key book lover represented a sharp contrast with Yasuhiro Sato, his bold, charismatic predecessor, who was vocal about his ambitions for Japan's second-largest lender but presided over a sharp decline during the last three years.
Sakai wasn't considered a favorite for the top job. But now that he has it, he is coming to grips with the scale of the turnaround needed for Mizuho, which has the best blue-chip corporate client base in Japan but the worst profits among the country's three mega-banks.