Nagasawa entered the film industry, winning the 5th "Toho Cinderella" competition, in which she competed with thousands of other 6th graders to appear in a Toho film. Many of her early roles were in Toho films, including Crossfire, Yomigaeri, ', ', and Crying Out Love in the Center of the World. Nagasawa's performance in Crying Out Love in the Center of the World received both a Blue Ribbon Award and a Japan Academy Prize for Best Supporting Actress. 2012. In 2007, she received a Japan Academy Prize nomination in the Best Actress category for her performance in the 2006 filmNada Sōsō. After a string of less notable films, including Gunjo and Magare Spoon!, she starred in the 2011 film adaptation of Mitsurō Kubo's mangaMoteki. Her performance in Moteki won Nagasawa a Blue Ribbon Award for Best Supporting Actress, and she was nominated for a Japan Academy Award in the Best Actress category. That same year Nagasawa expanded into voice acting by providing the voice of character "Umi Matsuzaki" in the Studio Ghibli film From Up on Poppy Hill. In 2016 she provided the voice for the character "Miki Okudera" in the international hit Your Name. . Her live action films have also received international attention. Kiyoku Yawaku , a live action adaptation of Ryo Ikuemi's manga series, was screened at the 17th annual Japanese Film Festival in Melbourne, Australia in 2013. Umimachi Diary, a live action adaptation of Akimi Yoshida's manga, competed for the Palme d'Or at the 2015 Cannes Film Festival. In 2017 Nagasawa starred in the Kiyoshi Kurosawa film Before We Vanish, which competed in the Un Certain Regard category at the 2017 Cannes Film Festival. Her performance in Before We Vanish also received recognition in Japan, winning a Mainichi Film Award for Best Lead Actress, and earning a nomination for a Japan Academy Prize for Outstanding Performance by an Actress in a Leading Role. In 2018, she starred in 50 First Kisses'', a Japanese remake of the 2004 American film50 First Dates.
Television
Nagasawa starred in many Japanese television drama series. Early supporting roles in the 2002 NHKasadoraSakura and the 2005 TBS Television live action manga adaptation Dragon Zakura led to more TV work, including a leading role in the 2007 Fuji TV series Proposal Daisakusen. Her performance in Proposal Daisakusen received the most votes in the Nikkan Sports Drama Grand Prix Best Actress category. After her initial success in television, Nagasawa continued to perform in both supporting and leading television drama roles. In 2009 she played a supporting role in the NHK taiga dramaTenchijin, and in 2010 she joined several other leading Japanese actors in the Fuji TV 50th anniversary mini-seriesWagaya no Rekishi. In 2012 her performance in the TV Asahi drama Toshi densetsu no onna won the 73rd Television Drama Academy Best Actress Award. In 2013 she learned Chinese to play a leading role in the Taiwan Television adaptation of the manga series Chocolat. Nagasawa returned to NHK in the 2016 taiga drama Sanada Maru.
