His father, an actors' agent, suggested he take on what became his first role, in the TV show "Kinpachi Sensei,"at the age of 16. His film debut was in the 1990 Swimming Upstream (Bataashi Kingyo; 1990), though his first major critical success was in Shunji Iwai's Fried Dragon Fish (1993). His first critical success internationally was Hirokazu Koreeda's Maboroshi no hikari (1995), in which he played a man who inexplicably throws himself in front of a train, widowing his wife and orphaning his infant son. His best known works internationally are the samurai films Gohatto (1999) and Zatoichi (2003), as well as the critically acclaimed film Akarui Mirai ("Bright Future"). It was on the set of Iwai's Picnic (1996) that he met and fell in love with J-Pop idol Chara. They married soon after learning she was pregnant with their first child, Sumile (Sumire – "violet" or "smile"). While best known for characters who are psychologically offbeat, if not downright psychopathic, e.g., Kakihara in Ichi the Killer (2001), Asano is described by those who know him as a down-to-earth family man. He has directed commercial TV spots for Chara and manages to find time to take Sumile and his son, Himi, to the zoo. Hesitant to identify himself as an actor, he most readily describes himself as a vocalist, referring to Mach 1.67, the band he has with director Sogo Ishii. He is also an artist and a model, most notably for Japanese fashion designers Jun Takahashi and Takeo Kikuchi, for whom he filmed a series of commercial spots directed by Wong Kar-wai, one released under the name wkw/tk/1996@7?55?hk.net.

During 2003, he acted in Katsuhito Ishii's The Taste of Tea, which was selected in the Cannes Film Festival. He appeared as the lead actor in Last Life in the Universe (2003), by Thai director Pen-Ek Ratanaruang, and starred in a follow-up film by Pen-Ek, Invisible Waves, in 2006.

He won the Most Popular Performer award at the 1997 Japanese Academy Awards for Acri and was nominated in the Best Supporting Actor category in 2004 for his performance in Zatôichi.

The extensive range of Asano's film career is due in part to his decision no longer to appear in television programmes, even though TV work in Japan is generally more lucrative than film acting.

--Wikipedia