Director / Writer

Kosai Sekine

関根光才

Tokyo, Japan

Filmmaker and Film Director working across Feature Film, Short Film, commercials, music video and art installation, known for cross-cultural storytelling and a contemplative visual style. Studied philosophy at Sophia University; took up photography during a short exchange in the United States and decided on filmmaking. The career path is documented in his own words: from 2000 he worked as a production assistant at the commercial production company SPOON, in the production department managing schedules, money and staffing, realised he wanted to direct, and moved to HUT because it had a directing department. Still not a director, he made a short for ADFEST: "Right Place" (2005), which won best foreign film at the New York short film festival and the Diesel Best Film prize at Raindance. The following year his Raindance trailer took the grand prix and three category wins at the Cannes young directors award, and shots ranked him the world’s number one new director. Went independent in 2008 and Joined Stink. Honda "Ayrton Senna 1989" (2014) took the Cannes Titanium grand prix and became the most-awarded advertising film in the world that year. Also a Cannes Lions Grand Prix, a D&AD Black Pencil, One Show and New York Festival golds, selection for the Saatchi & Saatchi new directors showcase, and he has served as a D&AD Juror. Music Video: Namie Amuro, MR.children, Tamio Okuda and akb48. Features and documentary: "Bungo: Stories of Desire - Sushi" (2012); "Love at Least" (2018, director and writer, from Yukiko Motoya), Shindo Kaneto Award Silver and the jury prize at france’s Kinotayo festival; "Tower of the Sun" (2018, documentary); "Stay Mum" (2024, director and writer); "Dust to Dust" (2024), a documentary on fashion waste and the environment, winner of the human/nature award at Tribeca; "Frontline" (2025); and "The Monster’s Prayer" due 2027. Founded the social art collective NOddIN in 2013. Studied philosophy at Sophia University, where an exchange programme in the US sparked an interest in photography and the decision to become a filmmaker. Started as a Production Assistant at an advertising film production company. Debuted in 2005 with 'Right Place', a darkly humorous short about a man with OCD, which won Best Foreign Film at the New York Short Film Festival. The following year he won the Young Director Grand Prix at Cannes Lions for 'Daughter', a spot for the Raindance Film Festival. In 2010 he directed Nike's 'Music Shoe' campaign with breakbeat unit hifana, creative technologists Rhizomatiks and W+K Tokyo, which redefined branded content and took Cannes Lions Silver in Film Craft, his second consecutive Silver. Works across feature film, documentary, short film, TVC, music video and art installation. Released two features in 2024: 'Stay Mum' (A Secret), a narrative feature starring An Watanabe about a woman with an unbearable past caring for a father with dementia while hiding an abused boy; and the documentary 'Dust to Dust', following Yuima Nakazato, the only Japanese designer showing at Paris Haute Couture Week, through fashion-waste mountains in Kenya to Tokyo and Paris to reimagine the future of fashion. 'Dust to Dust' won the 2024 human/Nature Award at Tribeca. Most recent work: 'Frontline' (2025). Represented internationally by Stink Films; managed in Japan by GLASSLOFT.