The 33-year-old Puerto Rican won the WBO junior flyweight title against Shokichi Iwata last March and followed that by adding the WBA belt when he surprised Kyosuke Takami on December 17.

He will look to continue his impressive run in the Orient when he meets former strawweight titlist Masataka Taniguchi at Korakuen Hall, Tokyo, on Friday.

"This will be a very interesting fight," Santiago (15-4, 9 KOs) told The Ring. "Taniguchi is a true warrior — strong, experienced, and a former world champion.

"However, the king of the division today is René "El Chulo" Santiago. I've already defeated two world champions on their home turf, and on April 3rd I'll be going after my third victory in Tokyo."

Despite being a decided underdog in both title fights, going overseas has proved a happy hunting ground for him.

"Iwata and Takami were two major challenges for me in 2025," he said. "They are young warriors who gave everything in the ring to win, but I was able to defeat both of them through skillful boxing and ring intelligence.

"Only my trainer, my family, and my team truly believed I could beat Iwata — and we proved it. Then we went after the unification bout with Takami, and we defeated him in the same year. Now my full focus is on the challenge ahead: Taniguchi."

Santiago remains a modest person, who despite last year's accolades and his newly found fame, still works a day job.

"I currently work 40 hours a week, Monday through Friday," he said. "I've been a custodian at the University of Puerto Rico in my hometown of Humacao for the past 12 years. I train in the mornings and work in the afternoons.

"Without a doubt, my life has changed over the past year. I've received many blessings from God and enjoyed tremendous success. I made history, and that will remain forever."

Having achieved more than most would have thought possible last year, Santiago intends to keep pushing the boundaries.

"My main objective is to defeat Taniguchi and then pursue the other world champions in my division," he remarked. "On March 15th, Iwata beat Knockout for the WBC world title. I would love the opportunity to fight him later this year."

His promoter, Tuto Zabala of All Star Promotions is proud of his fighter and welcomes the opportunity to return to Japan.

"He's demonstrated he's the best 108-pounder in the world," said the long-time promoter. "It's been an incredible ride, he's a great kid and he deserves what's happening to him. We're very excited to go back there and after this fight, he's eager to win more titles."

Taniguchi, rated at No. 9 by The Ring at junior flyweight, lost his first world title shot against WBO strawweight boss Vic Saludar (UD 12). However, he rebounded and claimed the same title when he upset Wilfredo Mendez (TKO 11).

He made one successful defense before losing to Melvin Jerusalem (TKO 2). He has gone 5-1 since, the lone loss came against future IBF 108-pound titlist Thanongsak Simsri (SD 12) for the OPBF title, but he has gone on to capture the national and OPBF titles when he stopped Takeru Inoue (TKO 5) in his most recent outing on August 3.