To provide: a novel compound that inhibits Ax1 and is useful as a treatment for diseases caused by Ax1 hyperfunction, as a treatment for diseases related to Ax1 hyperfunction, and/or as a treatment for diseases involving Axl hyperfunction； a salt of said compound； or a crystal of said compound or salt. [Solution] Provided are: a pyridone derivative having a tetrahydropyranyl methyl group represented by formula (I) and having various substituent groups； a salt of said derivative； or a crystal of said derivative or salt (Herein, R1, R2, R3, R4, R5, W, X, Y, and Z in formula (I) are synonymous with the definitions in the description.).
