"Zhònglì Huànxiǎng Qū (重力幻想曲) is a doujinshi album by Yu Jianliu. It contains 18 tracks, sung by Luo Tianyi, Kagamine Rin, Kagamine Len, GUMI, Hatsune Miku, and a guest, Ruan Xiaoqi. Track 18 is a version of the Star Guardian (元气星魂) OP (written by Yu Jianliu and sung by Ruan Xiaoqi)"