WBC flyweight champion Akira Yaegashi and WBC light flyweight champion Naoya Inoue will both defend their titles on Sept. 5 in Tokyo, their Ohashi Boxing Gym announced Monday.
The world doubleheader will be held at Yoyogi National Gymnasium Annex.
Making his fourth title defense, Yaegashi, 31, will take on the hard-hitting Roman Gonzalez of Nicaragua, who is aiming for his third championship belt after capturing both the WBA minimumweight and WBA light flyweight crowns.
Gonzalez, who is nicknamed "El Chocolatito," is an eye-popping 39-0, including 33 knockouts.
Asked at a press conference in Tokyo his impression of Gonzalez, Yaegashi said, "It's disturbing because he's really strong. Hopefully I can find a small opening to give me a chance to break through."
"He is the genuine article, the strongest of all challengers," added gym president Hideyuki Ohashi.
Inoue, 21, who claimed the title in his sixth professional fight in April — the fastest ever by a Japanese boxer — will make his first title defense against the 15th-ranked Samartklek Kokietgym, 29, of Thailand.
He had the option of moving up a weight class as he struggles to make weight but decided to remain at light flyweight.
"First of all, I want to perform my job as champion. I want to have an overwhelming victory," Inoue said.
Also on Monday, IBF minimumweight champion Katsunari Takayama formally announced he will meet WBO champion Francisco Rodriguez of Mexico in a unification title bout in Monterrey, Mexico, on Aug. 9. Takayama, 31, is aiming to become the first Japanese boxer to capture titles in boxing's four main governing bodies.