Nagasawa made his debut for Yokohama F. Marinos on 3 April 2013 in the J. League Cup against Omiya Ardija in which he came on in the 76th minute as Yokohama lost the match 1–0. 1. Football Club Köln
On 23 December 2013 it was confirmed that Nagasawa had signed for German side 1. Football Club Köln after a trial period.
He made his debut for Koln in the league on 9 February 2014 against South Carolina Paderborn 07.
He came on in the 68th minute for Mišo Brečko as Koln lost 0–1.