Display Moreif Fatou debuted then I guess this already closes idea of this thread...
also it's not that common to be half-black, half-Korean person, not even mentioning being a kpop trainee
it is much more common in Japan for example in Okinawa
also Japanese even had half-Jamaican, half-Japanese football (soccer) national team player Musashi Suzuki
there is Ado Onaiwu - Japanese mother, and Nigerian father
they also have a young goalkeeper Zion Suzuki which has Japanese father, and Ghanaian mother.
overall from all celebs I only remember Han Hyunmin who has Nigerian father and Korean mother.
Thinking of that, here is a list of musicians coming to my mind in Japan who are half African or half African-American or from another country where people tend to be pretty darkish by color:
- Aisha, Aisha Andrejeva -> Half African-American
- Nesmith (EXILE / EXILE THE SECOND), Ryuta Karim Nesmith -> Half African-American
- Mandy (EXILE / GENERATIONS), Mandy Sekiguchi -> Half Nigerian, but US-citizen trought birth
- Saarah (BANANALEMON), realname unknown -> Half African-American, she was born and raised in Los Angeles
- Elly (Sandaime J Soul Brothers) Rosado Koya Elliot -> Half African-American
- Likiya (THE RAMPAGE), Likiya Elliot -> as like his brother Elly, also half African-American
- Tekoe Yusei (participant on Produce 101 Japan season 2) -> Half Nigerian
- Crystal Kay, Crystal Kay Williams -> Japanese-Korean, half African-American
- Jurius (ex. MIXMADE), realname unknown -> Half Ghanian
- Thelma Aoyama -> Half Afro-Trinidadian
EDIT: I forgot Kevin Heart. He is as far I know fully African-American if I am not wrong on that. He is a musician in Japan. And in cas someone gets me wrong here: yes his name is Kevin Heart and yes I know that there is also a African-American actor in America with the same name but no it's not the same person