Ariana Miyamoto hadn't planned on entering a Japanese beauty contest because she thought her mixed-race origins meant she couldn't win. But she did enter and she won. She was crowned Miss Universe Japan at a pageant on 12 March. Then, to her surprise, her selection set off an internet firestorm.

The daughter of a Japanese woman and an African-American man, she stands out with her bronze skin and 5'7" height. But some on social media argued she didn't look Japanese enough to represent the nation at a beauty contest.

"That big mouth, that gaudy face. This is Miss Japan?" one social media commenter wrote. Another said she resembled an ant.

Miyamoto is determined to work hard to change that attitude. She said that her decision to join the beauty pageant was triggered by the suicide of a mixed-race friend.

"I was asked to join the competition in 2014 by an agency in Nagasaki, and although there were other biracial contestants, none of them won, so I declined, thinking I wouldn't win anyway. But that same year, I had a biracial friend who killed himself, so for him I wanted to change Japan. I got an offer again this year, so I decided to enter," she said after her work out routine at a Tokyo gym.

Miyamoto, who grew up in the coastal city of Sasebo in Nagasaki prefecture, Japan, says she has experienced many instances that made her feel excluded from Japanese society. She still receives English menus in Japan even though she speaks flawless Japanese and has a 5th degree mastery in Japanese calligraphy.

Miyamoto says her critics are vocal and estimates that about 60% of people are against her representing Japan in the contest, although many hide behind the anonymity of the internet. She said that neighbouring Asian nations are more accepting of her.

"I get voices of support from South Korea, and I think, these countries are neighbours but so different in their opinion of me," she added.

Miyamoto says she wants to make a difference, especially for the growing number of mixed-race children in Japan. In 2013, international marriages made up 3.3% of the total, government figures show, or four times the 1980 figure. Mixed-race children were 1.9% of those all born that year in Japan.