Nasu was born in Minamisatsuma on October 10, 1981. When he was a Komazawa University student, he joined J1 League club Yokohama F. Marinos in 2002. Although he is originally a center back, he became a regular player as defensive midfielder under new manager Takeshi Okada from 2003. He was also selected "Rookie of the Year award" in 2003. Marinos won the champions for 2 years in a row (2003-2004). However his opportunity to play decreased from 2006. In 2008, he moved to Tokyo Verdy. He played as regular player as his originally position, center back. However Verdy finished at the 17th place and was relegated to J2 League. In 2009, he moved to Júbilo Iwata. He played as regular player as center back in 2009 and as defensive midfielder in 2010. Júbilo also won the champions in 2010 J.League Cup. He also played as left side back from summer 2011. In 2012, he moved to Kashiwa Reysol. Although his opportunity to play decreased, he played many matches side back and center back. Reysol also won the champions in the 2012 Emperor's Cup. In 2013, he moved to Urawa Reds. He became a regular center back and scored 9 goals in 2013 season. He was also selected Best Eleven award in 2013. From 2016, his opportunity to play decreased behind new player Wataru Endo. In 2018, he moved to Vissel Kobe. Nasu retired at the end of the 2019 season.