Hasegawa was educated at and played for Shimizu Higashi High School. He won the national high school championship with his teammates including Katsumi Oenoki and Takumi Horiike. He continued his study and football at University of Tsukuba where he won the Kanto University League title in 1987. After graduating from the university in 1988, he joined Japan Soccer League side Nissan Motors. He contributed to the club winning the Emperor's Cup twice in 1988 and 1989. When Japan's first-ever professional leagueJ1 League started, Shimizu S-Pulse was founded in his local city. He joined the club in 1992 and re-united with his high school teammates Oenoki and Horiike. He helped the club to win the J.League Cup in 1996. He retired as a Shimizu player after the club won the second stage of the J1 League 1999 season. He played 207 league matches and scored 45 league goals in 7 seasons at Shimizu.
After retiring from the game, Hasegawa started working as a pundit for national television NHK. He was also installed as the general manager of two university clubs, Hamamatsu University and Fuji Tokoha University. He became the manager of Hamamatsu University and lead them to win the Tokai University League title and the Shizuoka Prefectural qualification for the Emperor's Cup. He acquired the S-class coaching license that was required to manage a J1 League club in 2004 and became the manager of his old club Shimizu S-Pulse in 2005. The club struggled and narrowly escaped relegation in the 2005 season but they fought back strongly in the 2006 season and finished 4th in the league; a position equaled in 2007. In 2008 Hasegawa led S-Pulse to the final of the J.League Cup and a fifth-placed finish in the league, a placing which included them being the strongest performing team in the second half of the season. He was rewarded with an extended contract which will keep him at S-Pulse until 2010. He left Shimizu after he led the club to the final of 2010-11 Emperor's Cup when his contract was expired. Hawegawa was appointed as a manager at J2 League club Gamba Osaka in 2013. The club won the champions in 2013 and was promoted to J1 League. In 2014, the club won all three major title in Japan; J1 League, J.League Cup and Emperor's Cup. He also was selected J.League Manager of the Year awards. In 2015, the club won the champions at Emperor's Cup and 2nd place at J1 League and J.League Cup. He resigned end of 2017 season. In 2018, Hasegawa signed with FC Tokyo.
In popular manga and anime seriesChibi Maruko-chan, a boy called Kenta kun occasionally makes an appearance. He loves football and is a classmate of title character Chibi Maruko. Momoko Sakura, the author of the manga, created this character after Hasegawa. Sakura and Hasegawa attended the same primary school during the same period.
