Kai Natsu Born On August 31 1983. Is A Japanese Singer And Songwriter. Born In Setagaya Tokyo She Graduated From Tamagawa University. Her Father Is Yoshihiro Kai From Kai Band 甲斐バンド And Her Mother Is The Former Actress Kahori Takeda. She Debuted As An Indie Artist With The Mini Album Yuugure Waltz 夕暮れワルツ In May 18 2005 And Went Major In 2007 With Namida No Seibun ナミダの成分 . Kainatsu kainatsu Official Website www.Kainatsu.Jp/index2.Html