A Japanese comedy duo and their management firm have apologised after the pair said during a live event that tennis star Naomi Osaka , who had just won the Pan Pacific Open at the weekend, “needed some bleach”. Ai Murakami and Aiko Kano, who are known as “A Masso”, made the remark during an event on September 22, the same day Osaka lifted her first trophy since winning the Australian Open in January, local media reported. The duo also said Osaka was “too sunburned”. In separate messages posted on the website of their management firm, Watanabe Entertainment, the comedians apologised for making “inappropriate, hurtful remarks”, but did not refer to Osaka, who is of Japanese and Haitian heritage, by name. “Though we should have thought about it, we made remarks that hurt many people, something we will never do again,” Murakami wrote. “We sincerely apologise for making the specific person feel uncomfortable, as well as for everyone else connected to the event. We also sincerely apologise for causing trouble.” Watanabe Entertainment, also without naming Osaka, added their own apology for “remarks inconsiderate of diversity in an era where diversity is respected”, saying the duo had been severely warned and steps taken to raise their awareness of the issue. A Masso has been performing as a duo since 2010. News of the racist comment, as well as the comedians’ apology, went viral on social media and sparked fury from Japanese netizens. Naomi Osaka embodies thorny issue of identity when it comes to sporting success “I'm surprised and shocked that ‘A Masso’ hasn’t been fired or even suspended for their racist remark about Naomi Osaka … Shame on you Watanabe Entertainment,” said Twitter user Shakytanaka, using the hashtag #racist. Other Japanese commenters said they were reminded of the racism that Brazilian footballer Dani Alves faced in 2014 – when a banana was thrown at him in a stadium. Alves was praised at the time for his response, when he picked up the banana and nonchalantly ate it. “A Masso’s Naomi Osaka joke is similar to that of the audience member who threw a banana at Alves,” wrote user Keinoset. “[Of course] A Masso should have apologised.” Another commenter, AnP7tool1, said they did not find the notion of “black skin being a bad thing” funny, and were reminded of Chinese laundry detergent brand Qiaobi’s notorious 2016 commercial, where a black man is pushed into a washing machine by a fair-skinned Chinese woman only to emerge as a light-skinned man. Neither Watanabe Entertainment nor Naomi Osaka’s management office in Japan was immediately available to comment. Osaka, who turns 22 next month, was born in Japan to a Haitian father and Japanese mother, and grew up in the United States . She has been widely hailed in Japan , which has traditionally seen itself as a racially homogeneous country, although a growing list of successful athletes with mixed heritage, such as Osaka herself, sprinter Asuka Cambridge and baseball pitcher Yu Darvish, are challenging that notion. In January, Japanese noodle company Nissin removed a controversial commercial which featured a cartoon character depicting Osaka with pale skin and light brown hair, after it prompted an outcry. Nissin said it had not intended to “whitewash” Osaka and promised to pay more attention to diversity issues. Additional reporting by Crystal Tai