Yukiko Kawasaki (川崎 由紀子) (1912-1989) and Takako Kawasaki (川崎 隆子) (1966-) were/are the cosplayers of Koishi Komeiji.
Yukiko Kawasaki was born in 1912 in Suzaka, Nagano Prefecture, Japan. She was interested in politics from the very beginning. After the introduction of Cosplay in 1925, she decided to cosplay one of her favourite characters, Koishi Komeiji. She also became elected Prime Minister of Japan as well, continuing to cosplay as Koishi. She was a great influence and had helped liberate Eastern Asia from the Western Aggressors, and kicked out the Communists in China and Vietnam. She launched Operation Perfect Cherry Blossom in 1931 to liberate Asia and by 1945 she got the job done. That is, minus Hong Kong and Macau. The reason why Hong Kong wasn't conquered is because Veronica Mehta, Englishwoman (of Indian descent) who cosplayed as Kogasa Tatara, was Prime Minister of Kogasanian Britain and since her stepping into power in 1940, the UK became very Eastern. Macau was ignored because Need For Speed 3: Hot Pursuit was released not too long ago and it featured Macau as an dangerous Empire City so it was avoided. Anyway, Yukiko Kawasaki went on and founded the Greater East Asia Treaty Organisation in 1945. Later on, she fought a war against the aggressive Australians in 1971, and so Kogasanian Britain and the Greater East Asia Treaty Organisation had declared war against Australia as well. However this was a first (and only) loss that Gensokyo had ever experienced.
Soon after the war, she continued to lead the Empire of Gensokyo until her death in 1989. Despite losing to Australia, everyone in Eastern Asia (including South East Asia and Sub-Indian continent) view her as a hero of Asia.
Takako Kawasaki was born in 1966 and is the daughter of Yukiko Kawasaki. She followed her mother's footsteps and got interested in politics as well. After her mother's death in 1989, she begun to cosplay as Koishi and became Prime Minister of Gensokyo, in which she renamed it back to Nippon-koku (Japan), in respect to new Emperor Akihito, who took power after Hirohito's death in the same year.
She was Prime Minister until Late 2011, when the real Koishi Komeiji appeared (via that special Russian invention), and took Prime Minister's role. However, Takako Kawasaki became Koishi Komeiji's helper.