Two famous and generous, million dollar prizes, Japanese literary awards are the Yomiuri and the Akutagawa Prizes.
My first question, how many of these are in English? I randomly selected Kaizu by Hideo Takubo, winner of the Yomiuri Prize. You can get the Japanese edition from Amazon but it looks like you can't get an English edition very easily. Hideo Takubo is famous. A book of his Fukaikawa (Deep River) won the Akutagawa Prize. That's 2 million right there. The Fukaikawa (Deep River) book was made into a movie called Fukai kawa (Deep River). It is on Amazon in English. The river in the title is the Ganges. I am guessing you will just have to be happy getting something in English by a winning author and not necessarily be able to get a translation of the winning piece.
Another clue would be the secondary English title. But that can be a problem because the titles vary. The Professor and his Beloved Mathematics is listed on the prize list. But it is found under The Professor and the Housekeeper by Ogawa Yôko in the English edition. Which then becomes The Professor and His Beloved Equation for the title of the movie. Be careful when buying the movie because it might not play on your DVD because of the whole Region thing.
The Akutagawa Prize was established in 1935 in memory of Ryūnosuke Akutagawa. Ryūnosuke Akutagawa is the Japanese Edgar Allen Poe. Ryūnosuke Akutagawa, March 1, 1892 – July 24, 1927, died of an overdose of barbituates. He was fearful he was suffering from an inherited mental disorder. He wrote over 150 short stories and has the title of being the Japanese short story father. His work is readily available in English and even has one 99 cent title on Kindle.
The Akutagawa Prizes are awarded twice a year, every six months. The Akutagawa Prizes are not so readily available in English. If you look for The Anonymous Tip of a Virgin by Akiko Akazome you might not be able to find it. You may need to make a Japanese friend in to avoid driving yourself crazy not being able to find translations.
The Yomiuri Prize was established in 1948. Yomiuri Shinbun Company wanted to promote culture in Japan. Yomiuri Shinbun is a Japanese newspaper with the largest circulation of any newspaper in the world. 14,323,781.
The Yomiuri Prize has morphed from 4 to 6 categories. The six prizes are novels, plays, essays and travel journals, criticism and biography, poetry, and academic studies and translation. I wonder if the million dollars goes to each category.