Shigenobu Okuma (1838-1922) was a Japanese diplomat, government official and educator, who served as Prime Minister of Japan
He was opposed to the Satsuma and Chosu Clan factions in the Meiji Restoration, pushing for constitutional government. He also opposed Takamori Saigo proposal for Korea: "to begin diplomatic relations with Korea in the hope that Korean refusal would precipitate a Japanese punitive expedition (this proposal is known as “Seikanron”), Ōkuma objected to this proposal on the grounds that domestic affairs should be given priority."
He founded Waseda University.
Party politicsAritomo Yamagata since the early Meiji days. When, in 1920, Yamagata opposed the marriage of Princess Nagako to Prince Hirohito, alleging she was genetically impure, Okuma said
As for Prince Yamagata, it is incumbent upon him to resign all the public office he holds, to say nothing of renouncing his treatment as a genro, so as to apologize to the emperor and to the nation. Otherwise, it would be impossible to placate the nation, which feels high resentment against his attitude. 
- Shigenobu Okuma: A Short Biography, Wakeda University
- William Theodore De Bary (2005), Sources of Japanese tradition: From earliest times to 1600, Columbia University Press, p. 826
- Sterling Seagrave and Peggy Seagrave (1999), The Yamato Dynasty: the secret history of Japan's imperial family, Broadway Books, ISBN 07677904066, p. 155