Etsuko Yakushimaru(やくしまる えつこ,Yakushimaru Etsuko) is a Japanese singer, producer, and composer. She is known for her solo works including theme songs in several anime series, such as Arakawa Under The Bridge, Space Dandy, Sailor Moon Crystal, and Mawaru Penguindrum. As well as being the lead vocal of the rock band Sōtaisei Riron, she also works as an illustrator and narrator. Initially, she did not reveal her face to the public, until the artist and her band was featured in the July 2009 edition of Studio Voice magazine. She also goes by the alias of Tika α (ティカ・α) when credited for lyrics and composing.