1. A computer-readable recording medium having stored therein a program causing a computer to execute a category creating process comprising: receiving a piece of music; extracting video image information that is included in the music received at the receiving and decomposing the extracted video image information with respect to each characteristic of the extracted video image information; and creating, with respect to each piece of video image information decomposed at the decomposing, a category that represents the characteristic of the piece of video image information.