Tsuki Fukutomi, known mononymously as Tsuki, is a Japanese singer, lyricist, dancer, model and MC under MYSTIC STORY. She is a member of the girl group Billlie and a former member of the Japanese girl group 7+ME LINK and its sub-unit MAGICOUR. Tsuki Fukutomi, known mononymously as Tsuki, is a Japanese singer, lyricist, dancer, model and MC under MYSTIC STORY. She is a member of the girl group Billlie and a former member of the Japanese girl group 7+ME LINK and its sub-unit MAGICOUR.