What is "foo?"

"Foo?" (Stylized as foo?) is the second album by the Japanese rock band Porno Graffitti, it was released on February 28, 2001.

Album title, because the second album, but it was taken from "Hi,Fu,Mi" (ひぃふぅみぃ/One,Two,Three) of "Fu", "Fuu" Japanese sigh at the fact that we arrived breath, Who? is also over.