(Sharon Myoui is an American from San Antonio, Texas. She might say now that she gave up her US citizenship but in Japan it is not mandatory to give it up as long as the person does not exercise US citizenship in Japan so her real status is unknown.)
there were some attempts to put Japanese members in KPop groups, but they mostly occurred in smaller outfits with no lasting changes. Lee Sooman's older brother had run a group, Sugar, with a Korean-Japanese member but it didn't last long.
Sana and Momo (there were a few who left) were to be released in a JYP group intended for Japan, but because of various events that became impossible so JYP debuted them in Twice.
Until around March 2016, Twice was checked by GFriend, whose members were , I have to say, visually challenged but had better skills. Plus the infamous Huang An shit seriously limited the reach of Tzuyu.
So, Sana and Momo, plus Sharon (a Japanese-American), were unleashed in Cheer Up, and simply obliterated Gfriend and the rest is history.
The success of Sana and Momo opened the floodgate for Japanese members in KPop, and now even nugu groups like CSR have a Japanese member. It is nowdays strange to have a Korean-only act like Fifty Fifty.
The names of Minatozaki Sana and Hirai Momo will be enshrined as the Japanese pioneers in KPop for ever.
