Ken Hirai has been played on NTS shows including Bo Ningen, with Lakuen (楽園) first played on 1 August 2023.

Ken Hirai (平井 堅 Hirai Ken, born January 17, 1972) is a Japanese R&B and pop singer. Since his debut, Hirai has worked as a model, actor, composer, lyricist, singer, and spokesperson.

During his career, Hirai has released 32 singles and 11 albums until October 2010. According to Oricon, his single Hitomi wo Tojite (Close Your Eyes) became the best-selling single of 2004 in Japan, while his compilation album Ken Hirai 10th Anniversary Complete Single Collection '95–'05 "Utabaka" became the best-selling album of 2006 in Japan….