Matsu made her stage debut role in Ninjō-banashi: Bunshichi Mottoi at Kabuki-za. Her first lead role in television was in the NHK Drama Hana no Ran and starred in the NHK Drama Kura. Because Shirayuri Gakuen, her high school, prohibited working in the industry, she was transferred to Horikoshi High School. Matsu starred in the drama Long Vacation after matriculating to college. She had a supporting role, but establishEd in full-scale her position as an actress because the drama was a major hit. She hosted the 47th NHK Kōhaku Uta Gassen. She debuted with the single “Ashita, Haru ga Kitara”. She returned to the show as a singer on the last day of the year. In an interview with NHK, Matsu recalled the incident that triggered her musical debut. At the wrap-up ceremony of the drama, she sang karaoke which was heard by its director who suggested that she give singing a try. Although she refused at first, as she was not confident enough in her singing, Matsu accepted because she saw it as “[a] chance that not everyone got”. In the same year, she starred in the drama Love Generationin a leading role. In 2001, she starred in Hero. In 2003, she published a photo essay book, Matsu no Hitorigoto, through Asahi Shimbun Publishers. In September 2004, she released “Toki no Fune”, which was composed by Akeboshi. It is similar to the song, “A nine days’ wonder”, which was released after the “Toki no Fune” single. The single contained a cover of Akeboshi’s “White Reply” previously recorded on her sixth album, Harvest Songs. Matsu won the Best Actress of the Year of the 29th Hochi Film Award and the 28th Japan Academy Prize at the same time for The Hidden Blade. In July 2006, she and Takuya Kimura starred in a special one-night edition of Hero. In October 2006, Matsu was in a weekly drama for the first time in over three years titled Yakusha Damashii for Fuji TV alongside Makoto Fujita. Matsu left the third concert tour in May 2007 to commemorate her tenth year as a singer. In her album Cherish You, the song “Ashita Haru ga Kitara” was redone to combine her voice as a 20-year-old with her current one. On November 27, 2014, Matsu revealed on her official website that she was pregnant with her first child. On March 30, 2015, she gave birth to her daughter. She revealed on her website that the baby was 3466 grams. On February 9, 2020, Matsu was called to join Idina Menzel, Aurora and eight more of Elsa’s international dubbers to perform the song “Into the Unknown” at the 92nd Academy Awards. Every international performer sang one line of the song in a different language: Maria Lucia Heiberg Rosenberg in Danish, Willemijn Verkaik in German, Matsu in Japanese, Carmen Sarahí in Latin American Spanish, Lisa Stokke in Norwegian, Kasia Łaska in Polish, Anna Buturlina in Russian, Gisela in European Spanish and Gam Wichayanee in Thai.

Matsu was born to a family of buyō and kabuki actors, including her father Matsumoto Hakuō II, her mother and businesswoman Noriko Fujima, her uncle, Nakamura Kichiemon II, her elder brother Matsumoto Kōshirō X, her sister Kio Matsumoto, and stage director Kazuhisa Kawahara. She married guitarist and record producer Yoshiyuki Sahashi on December 28, 2007. Her married name is Takako Sahashi (佐橋隆子, Sahashi Takako). She also has the name of Natori (the accredited master) of the Matsumoto school of Nippon Buyō (Japanese dancing); Shodai Matsumoto Kōka (初代 松本 幸華, “Kōka Matsumoto the First”). She chose the surname “Matsu” to honor the family. In a interview, she and her siblings are close to their mother.