This is the promo song accompanying the book "Gengogakuteki Rappu-no Sekai [The Linguistic World of Rap Music]" by Dr. Shigeto Kawahara. The rapper--Mummy-D, Shinpeita, TKda Kurobuchi & SHEER--wrote the lyrics as testimonials of how they felt when they encountered the linguistic analyses of rap songs by Dr. Kawahara.