Yamato Holdings shares surged as much as 15% in Tokyo, their biggest rally in 18 years, after Farallon Capital Management disclosed a stake of just over 5% in the Japanese courier company and called for management reforms.

Farallon urged Chairman Yutaka Nagao to leave the board, saying the company should pursue “bold” changes. The investor also called for all board members except President Toshiyuki Sakurai to be outside directors.

Japan’s stock market was closed on Tuesday for a holiday.

Sources: Bloomberg Markets.