For decades, boards allowed former executives to linger on as highly paid advisers, without offering shareholders much detail about their roles. Now, there are signs that cushy retirement gigs may no longer be a sure thing.

Japan's largest drugmaker, Takeda Pharmaceutical Co., in an unusual letter to shareholders this month, said retiring Chairman Yasuchika Hasegawa will stay on as an adviser — but getting only 12 percent of his current compensation with no bonus, corporate car or full-time secretary. The company also emphasized that he would play a limited role in executive decisions.

Takeda issued its statement detailing Hasegawa's pay and the reasons for him to stay on after a group of 15 unnamed shareholders put in a proposal against having advisers and demanded that the company seek the approval of investors before making such appointments. Having former executives in advisory roles allows them too much influence over corporate decisions, the group argued. The shareholder proposal will come up for vote at the Takeda annual meeting on Wednesday.