Yui made her acting debut in the full-length feature film '' Song of the Sun '' ( Taiyou no uta , タイヨウのうた ) , which opened on June 17 , 2006 . The film was screened at the 2006 Cannes Film Festival . She had a unique way of approaching her role , such as imagining unscripted conversations between other characters and hers as well as staying in her character 's room and fitting the aberrant sleeping patterns of her character to give herself a sense of her role . Yui attended the Japan Academy Prize , winning Best Newcomer Award for '' Midnight Sun '' . Prior to the release of the movie , Yui released her fifth single " Good-bye Days , " written specifically for the film . The single is her highest selling single , with more than 200,000 copies sold . All three tracks on the single are featured in '' Midnight Sun '' . The single also re-released the track " It 's Happy Line , " originally released on her debut single
2006 Cannes Film Festival
2006 Cannes Film Festival
Yui (singer)