Tokyo Olympics creative director Hiroshi Sasaki is resigning after making demeaning comments about a well-known female celebrity.
The news is yet another setback for the postponed games and another involving comments about women.
The Olympics are to open in just over four months, dogged by the pandemic, record costs, and numerous scandals.
In February, the president of the organising committee Yoshiro Mori was forced to resign after making sexist comments, saying women talk too much in meetings.
And two years ago, the head of the Japanese Olympic Committee Tsunekazu Takeda was also forced to step down in a bribery scandal connected to vote-buying involving International Olympic Committee members.
Mr Sasaki was in charge of the opening and closing ceremonies for the Olympics, which are to begin on July 23.
He released a statement early on Thursday saying he was stepping down and said he called Seiko Hashimoto, the president of the organising committee, and tendered his resignation.
He said: “For Ms Naomi Watanabe, my idea and comments are a big insult. And it is unforgivable.
“I offer my deepest regrets and apologise from the depth of my heart to her, and those who may have been offended by this.”