To gain influence in the proper region, Beijing and Tokyo are both courting South Asian countries that border the disputed South China Sea, the majority of which China claims.
In October, President Joko Widodo will swear the former head of the special forces and present defense secretary.
Human rights organizations are concerned about his vote because he is accused of abusing his military service. Prabowo, who was found by a military government to possess kidnapped student protesters in 1998, denies the charges.
In Tokyo, Prabowo met with Minoru Kihara, the defense secretary of Japan.