Hiroshi Nakamori in the eighth round after being floored again in round two. In May 2011, he went to Guadalajara, Mexico for a two-week workout at Julian Magdaleno Gym () where Saúl Álvarez has been training. He defended his title three times all by stoppage before vacating it. OPBF title Arakawa successively captured the vacant OPBF lightweight title via a split decision over Filipino fighter Jay Solmiano in October 2011. It was a tough-fought close bout with Solmiano scoring a knockdown in round two. After defending his title against fellow Japanese Ryūji Migaki by a unanimous decision, he travelled to Los Angeles to spar with Miguel Vázquez and others for over a month. He stopped compatriot Takehiro Shimada in round eight in his second defense in August 2012 while throwing over a hundred punches each in two rounds, and then vacated his title. Arakawa vs. Daniel Estrada In November 2012, Arakawa competed with Mexican Pedro Daniel Estrada in Mexico City on the main event of the Gala Ring Telmex 2012. It was a WBC Silver lightweight title bout and was a title eliminator with a shot at Adrien Broner on the line. After eleven rounds, Estrada was called as the winner with a technical decision. Its refereeing processes and outcome caused controversy in Japan, and more in Mexico. The WBC's official Twitter account tweeted as follows: "There was a controversy in that fight where the winner would be fighting for the title, but because there was this problem, the WBC demanded a rematch. That is a fight for all ring officials to look at." A rematch between them never happened. Arakawa vs. Omar Figueroa On July 27, 2013, Arakawa made his U.S. debut at the event dubbed Knockout Kings II at the AT&T Center in San Antonio, Texas. His opponent fighting out of the blue corner was the undefeated Mexican-American fighter Omar Figueroa, Jr. and the WBC interim lightweight title was at stake. The interim title bout was made when reigning champion Adrien Broner decided to challenge the WBA welterweight title. The incredibly tough fight that was aired live on Showtime Championship Boxing, and on WOWOW in Japan, ended in Figueroa's victory by a unanimous decision. RingTV.com's Douglass Fischer told as follows: " no fighter raised his stature during the course of one fight as much as Japanese veteran Nihito Arakawa did with the heroic effort he put forth against