Alto Mare" is a compilation album by Japanese Internet label "windjammer". As its advance single, Trackmaker/Vocaloid P "ueil" × and net singer "WaMi". The song "Niu" by trackmaker/vocaloid P "ueil" and net singer "WaMi" is distributed as an advance single. The theme of the compilation's worldview is interpreted by "ueil" and extended by "WaMi" with her voice, and the song is a song in which the words invade the space in your heart.