On February 10, 2004, Arakawa made a start to his professional career with a first round
knockout at the
Korakuen Hall. He rematched Katō in September 2006 where he suffered his first loss in a close decision. Issei Nakaya of Hachioji Nakaya Promotions had promoted Arakawa until the end of 2014.
Regional title fights In September 2008, Arakawa faced
Filipino Randy Suico for the
OPBF lightweight title, but the fight ended in a
majority draw.
Japanese title Arakawa won the Japanese lightweight title via a
majority decision from Akihiro Kondō in April 2010, after being knocked down for the first time in his career in round one. In his second defense in January 2011, he stopped 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 Omar Figueroa Jr. last July in San Antonio," Fischer later described.
Arakawa vs. Jorge Linares On March 8, 2014, Arakawa came back to the ring to face Japan-based
Venezuelan Jorge Linares in a ten-round WBC title eliminator, with a mandatory shot against Omar Figueroa on the line. It was featured on the undercard of the fight between Saúl Álvarez and
Alfredo Angulo at the
MGM Grand Garden Arena in
Las Vegas, Nevada. Figueroa was to fight in the same event, but a wrist injury forced him to postpone it. That is why Arakawa–Linares was carried live on
Showtime pay-per-view. Arakawa was again fighting out of the red corner, but lost in a unanimous decision. In the second half of 2014, he defeated Kondō in their rematch in July, and lost to Katō in their rubber match in December, both by unanimous decision at Korakuen Hall. Arakawa then transferred to Hitoshi Watanabe's Watanabe Boxing Gym in April 2015. Among his new stable-mates are
Takashi Uchiyama,
Kōhei Kōno and
Ryōichi Taguchi. == Two nicknames ==