After graduating from university, Hasegawa was part of a Kantō region representative team which toured New Zealand in 1995.
His first cap for Japan was on 29 June 1997, against Hong Kong in Tokyo, where he played as a replacement flanker.
Hasegawa was also called up by the then-national coach Seiji Hirao to play for Japan in the 1999 Rugby World Cup, where he played all the three pool stage matches in the tournament.
From 1995, after his graduation from Chuo University, he joined Suntory club, with which he won the Japan Company Rugby Football Championship in 1997 and 1998, as well the All-Japan Rugby Football Championship in 2000 and 2002.
He retired in 2007 and became a forwards coach initially for Suntory and later for Yamaha Jubilo.