Yu Hirai was born in 1963 in Japan, which she left for good at the age of 20 for Europe. From 1985 to 1988, she studied at the École Nationale Supérieure des Arts Visuels La Cambre in Brussels where she took a particular interest in drawing technique. After a three-year stay in Barcelona, she lived in Berlin from 1994 to 1999, where she started to work with photography. In 1999, Yu Hirai took part in the residency programme at Light Work (Syracuse University/USA). After a second residency at the Irish Museum of Modern Art (Dublin/Ireland), she received a bursary from UNESCO Aschberg and the National Fund for Culture and Arts for a photographic series in Mexico. In 2002 and 2003, she stayed at the Cité Internationale des Arts in Paris.
Since 1988, she has regularly presented her work in the form of solo exhibitions, (2017, Forest of Questions, Japan ; 2015, Entre Chien et Loup, Les Bains Révélateurs, Roubaix ; 2013, Frontières, Galerie Sator, Paris ; 2005, Le Petit Cirque, Belgium…). 
In 2017, Yu Hirai won the parcours prize at Phot’Aix, which allowed her to do a solo show the following year at Galerie de la Fontaine Obscure in Aix en Provence. Since 2010, she has taken part in numerous festivals, including Dali International Photography Exhibition in China in 2019, also Mons 2015 in Belgium.  Concerning group shows, in 2001, she took part in the Next Génération : Art Contemporain d’Asie at Passage de Retz in Paris ; in 2003, she showed at Jeune Création at the Grande Halle de La Villette in Paris ; in 2007, in Art for Art’s Sake at Palazzo Zambeccari in Bologna, Italy; in 2012, she was invited to show her photographic series at Seika University in Kyoto, Japan ; in 2019, her photographs were shown at Tokyo Metropolitan Museum of Art in Japan.