Question: Hiroaki Sato fought which Japanese mixed martial artist born on July 21, 1981?

Context paragraphs:
Hiroaki Sato (figure skater): Hiroaki Sato (Japanese: 佐藤洸彬 ; born December 6, 1995) is a Japanese figure skater.  He was named in Japan's team to the 2015 World Junior Championships in Tallinn, Estonia.  Sato ranked 17th in the short program, 14th in the free skate, and 15th overall.  He has won three senior international medals.

Yushin Okami: Yushin Okami (岡見 勇信 , Okami Yūshin , born July 21, 1981) is a Japanese mixed martial artist currently competing in the Light Heavyweight division of the UFC.  A professional competitor since 2002, Okami has also formerly competed for PRIDE, Pancrase, M-1 Global, World Series of Fighting, and Professional Fighters League.  He holds notable wins over Mark Munoz, Hector Lombard, Alan Belcher (twice),Anderson Silva (Via DQ), Nate Marquardt, former MMA fighter Evan Tanner and Mike Swick.

Hikaru Sato: Hiroaki Sato (佐藤 弘明 , Satō Hiroaki , born July 8, 1980) is a Japanese professional wrestler and mixed martial artist, better known by the ring name Hikaru Sato (佐藤 光留 , Satō Hikaru ) .  Sato started his MMA career in February 2000, fighting for Pancrase Hybrid Wrestling.  During the next eight years, Sato fought, on average, five times a year, compiling a record of 18 wins, 19 losses and four draws, which included fights against the likes of Keiichiro Yamamiya, Nathan Marquardt, Ryo Chonan and Yushin Okami.  In May 2008, Sato transitioned into the world of professional wrestling, when he was signed by the Dramatic Dream Team (DDT) promotion.  He has since had ten MMA fights.  In November 2010, Sato first became a triple crown trios champion with Michael Nakazawa and Tomomitsu Matsunaga and then also won DDT's top singles title, the KO-D Openweight Championship.  Sato remained affiliated with DDT until January 2014.  He is currently working for the All Japan Pro Wrestling promotion, where he is a former two-time World Junior Heavyweight Champion and three-time All Asia Tag Team Champion, while also being a three-time winner of the Jr.  Tag Battle of Glory tournament.

Hiroaki Sato: Hiroaki Sato (佐藤 紘彰 , Satō Hiroaki , born 1942) is a Japanese poet and prolific translator who writes frequently for "The Japan Times".  He has been called (by Gary Snyder) "perhaps the finest translator of contemporary Japanese poetry into American English".

Yasuhito Namekawa: Yasuhito Namekawa (滑川康仁 , Namekawa Yasuhito ) (born October 27, 1974) is a Japanese mixed martial artist who competes in the light heavyweight division.  Namekawa made his Mixed martial arts debut for Fighting Network Rings in 1998.  He fought in mainly Shoot fighting bouts until 1999 when Rings introduced the "King of King Rules".  Throughout his career, Namekawa has fought for organisations such as Rings, Deep and Pride FC.  His last fight to date was in 2008, with a professional Mixed martial arts career spanning ten years.

Hiroaki Sato (footballer): Hiroaki Sato (佐藤 弘明 , Satō Hiroaki , February 5, 1932 – January 1, 1988) was a Japanese football player and manager.

Burton Watson: Burton DeWitt Watson (June 13, 1925April 1, 2017) was an American scholar best known for his numerous translations of both Chinese and Japanese literature into English.  Watson's translations received many awards, including the Gold Medal Award of the Translation Center at Columbia University in 1979, the PEN Translation Prize in 1982 for his translation with Hiroaki Sato of "From the Country of Eight Islands: An Anthology of Japanese Poetry", and again in 1995 for "Selected Poems of Su Tung-p'o".  In 2015, at age 88, Watson was awarded the PEN/Ralph Manheim Medal for Translation for his long and prolific translation career.

Hiroaki Matsutani: Hiroaki Matsutani is a Japanese mixed martial artist.  He competed in the Lightweight division.

Hiroaki Yoshioka: Hiroaki Yoshioka (born January 3, 1974) is a Japanese mixed martial artist.  He competed in the Strawweight, Flyweight and Bantamweight divisions.

Silk and Insight: Silk and Insight (Kinu to Meisatsu) is a 1964 novel by the Japanese writer Yukio Mishima.  The subject of the novel is taken from an actual strike in Japan in 1954 at Omi Kenshi, a silk thread and fabric manufacturer, which lasted for 106 days.  It was translated to English in 1998 by Hiroaki Sato as the seventh volume in The Library of Japan series, produced by the Pacific Basin Institute at Pomona College.

Supporting paragraphs: Hikaru Sato Yushin Okami
Answer: Yushin Okami