TOKYO: Joshua and Benny Safdie's Heaven Knows What, the story of a young heroin addict who finds love in the streets of New York, took the top prize at the Tokyo International Film Festival on Friday.

The Safdie brothers also won the best director award for the U.S.-French production, which is based on a real-life account of the female lead, Arielle Holmes, and co-stars Caleb Landry Jones of X-Men: First Class fame.

"It was very simple," competition jury president James Gunn said on selecting the winner. "This was the film that inspired us the most and got us the most excited."

The Guardians of the Galaxy director added that Heaven Knows What was the most balanced of the films in competition in terms of imagery, story and acting.

"Heaven Knows What" was one of 15 films competing for the $50,000 Tokyo Grand Prix, after premiering in Venice and screening at Toronto and New York.

The main competition lineup featured a strong slate of other films making their Asian premieres after screening at major festivals, including 1001 Grams, Norway's Oscar submission for Best Foreign Language Film, and French thriller The Connection.

Lone Japanese entry Pale Moon, about an ordinary housewife who becomes involved in embezzlement, won the Audience Award.

Outside the main competition, this year's festival put greater emphasis than previous years on animation, highlighting Japan's strength in anime.

The festival opened with the world premiere of Big Hero 6, Disney Animation's next big feature after last year's hit Frozen.

It also featured a section on the works of Evangelion animator Hideaki Anno, while Super Mario creator Shigeru Miyamoto unveiled his 3D PIKMIN Short Movies, based on the Nintendo game characters.