(Bloomberg) -- SoftBank Group Corp.’s Chief Strategy Officer Katsunori Sago is planning to leave after less than three years at the company, people familiar with the matter said, as other executives gain prominence at the Japanese investment conglomerate.

The Goldman Sachs veteran who joined SoftBank in June 2018 intends to resign by the end of March, one of the people said, asking not to be identified because the details are private. His actual departure may not take place till June, another person said. SoftBank representatives had no immediate comment.

The 53-year-old is a key member of founder Masayoshi Son’s inner circle and something of a celebrity in Japan’s world of finance. Prior to joining SoftBank, Sago spent more than two decades at Goldman Sachs Group Inc., rising to become vice chairman of its operations in the country. During a three-year stint at state-owned Japan Post Bank Co., he spearheaded a portfolio shift away from sovereign bonds.

But little is known about his work at SoftBank. The company has never clearly defined his role as CSO, a position that did not exist prior to his joining. Over the past few years, he has assembled a small team of former Goldman bankers and set up an investment department in April.

Rumors about his departure began to circulate late last year as Sago seemed increasingly adrift while other Son lieutenants, including Chief Operating Officer Marcelo Claure and Vision Fund head Rajeev Misra, began to take more prominent roles in public markets and startup investment.

In November, SoftBank said Sago and three other directors will leave the board in an effort to increase the proportion of outside directors and improve corporate governance. The executive earned 1.11 billion yen ($10.2 million) in the year ended March 2020, a 13% increase from the previous year.

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