Tatsuya Kitani (キタニタツヤ, Kitani Tatsuya; born 28 February 1996) is a Japanese musician, singer, lyricist, composer, and arranger. He is the bassist of the trio band Sajou no Hana. He was also active as a Vocaloid producer under the name of "Konnichiwa Tanita-san" (Hello Tanita-san). The affiliated office is Smile Company, and the affiliated label is Echoes under Sony Music Entertainment Japan. His official fan club is "Club Unreality".
Source: “Tatsuya Kitani”, English Wikipedia (CC BY-SA 4.0), excerpt