Tesla announced Thursday that it is appointing Hiro Mizuno to its board of directors.

Mizuno was most recently the chief investment officer of Japan's $1.5 trillion government pension fund, the largest such retirement pool in the world.

The former investment banker's appointment as a director could mark an end to a tumultuous year-and-a-half for Elon Musk's board of directors.

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Hiromichi (Hiro) Mizuno, a Japanese investment manager and businessman, is joining Tesla's board of directors, the company announced in a regulatory filing Thursday, punctuating a tumultuous 18 months for the company's board.

Mizuno most recently served as the chief investment officer of Japan's $1.5 trillion government pension fund, the largest pension fund in the world, which owns roughly $874 million worth of Tesla stock. Before that post, Mizuno worked in finance roles in New York, San Francisco, and other global business centers.

"We are excited that Hiro has joined our mission to accelerate the world's transition to sustainable energy," Tesla said in a blog post.

Shares of Tesla were little changed in after-hours trading Thursday following the announcement.

His arrival signals yet more change for Tesla's board, which has seen a seismic shift since chief executive Elon Musk's legal tussle with US regulators. As part of a settlement with the Securities and Exchange Commission, the company agreed replace Musk as chairman and add two new independent directors.

First, Australian telecom executive Robyn Denholm took over leadership of the board in November 2018, two months after the $40 million settlement. Her addition was followed shortly after by the addition of Oracle billionaire Larry Ellison and Walgreens executive Kathleen Wilson-Thompson as directors in December 2018.

Following the departures of four other directors and Musk allies — Antonio Gracias, Steve Jurvetson, Brad Buss, and Linda Johnston Rice — this year, the company's board will be reduced to just seven directors. The smaller board will allow Tesla to "operate more nimbly and efficiently, while maintaining new ideas, expertise and experiences on the Board," it said last year.