A star-shaped vinyl ether polymer, comprising a central core and an arm portion bonded to the central core, wherein: the arm portion comprises a repeating unit derived from a vinyl ether monomer; the star-shaped vinyl ether polymer comprises a structure represented by the following Formula (1): —Y—Ar1—N═N—Ar2  (1); wherein Y represents an ether bond, a thioether bond, a group —NH—, or a group —OR1—*, R1 represents an alkylene group, * represents a position bonded to Ar1 in Formula (I), Ar1 represents a substituted or unsubstituted divalent aromatic hydrocarbon group, and Ar2 represents a substituted or unsubstituted monovalent aromatic hydrocarbon group; and particularly the central core is formed by crosslinking of a polyfunctional coupling agent, wherein the polyfunctional coupling agent is a compound represented by the following Formula (3): wherein R5 to R8 each independently represent a hydrogen atom or a methyl group, and R9 represents a divalent organic group.