The winner of the Miss Japan pageant, who was born in Ukraine, has stepped down from her position following reports of her involvement in an affair with a married doctor.

Karolina Shiino's nomination in January initially stirred controversy, with some right-wing individuals questioning the awarding of the title to a naturalized Japanese citizen.

A scandal then erupted over her private life when weekly magazine Shukan Bunshun reported on her extramarital relationship, taboo for beauty pageant contestants, who are held to squeaky-clean moral standards.

Japanese entertainment personalities who have affairs, dabble in drugs or suffer other scandals also often find themselves shunned by their fans and employers.

The Miss Japan Association said Monday that it had accepted a request from Shiino to return the crown for "personal reasons," adding there would be no Miss Japan for 2024.

Shiino said she wanted to "deeply apologize" to those involved, including the man's wife, on the same day her management agency said she had confirmed the affair.

At first "I couldn't speak the truth due to chaos and fear, I apologize to those who believed in me and supported me," the 26-year-old said on Instagram.

"I take the situation seriously and have relinquished the Miss Japan Grand Prix title," wrote the model, who moved to Japan around the age of five.

In a statement Monday, Shiino's agency said she told them she had begun seeing the man believing him to be divorced, but continued the relationship after learning he was still married.

Miss Japan, first held in 1950, is awarded for "Japanese-style beauty" consisting of "inner beauty, beauty in appearance and beauty of actions," its website says.

After Shiino's nomination attracted attention online, people quickly weighed in on social media.

"It doesn't matter if she is Jewish-Ukrainian or not, but I can't accept her character... Why is she Miss Japan?" one user wrote on X, formerly Twitter.

Others wrote in support of Shiino on her Instagram post.

"You have Japanese spirit. I don't think such (a) personal private thing should be a reason for you to step down but this is Japan," said a reply with nearly 350 likes.