Thermoplastic elastomer composition, member, weather seal, and corner member for weather seal

Provided is a thermoplastic elastomer composition which has high adhesion to vulcanized rubber and dynamically crosslinked thermoplastic elastomers (TPVs), and has excellent flexibility, weather resistance and moldability. Further provided are a member having a portion made of the thermoplastic elastomer composition, a weather seal comprising the member and a corner member for a weather seal having a portion made of the thermoplastic elastomer composition. The thermoplastic elastomer composition is, specifically, a thermoplastic elastomer composition comprising an olefin-based rubber (I), a hydrogenated block copolymer (II) described below, a polyolefin-based resin (III), and a softening agent (IV). The content ratio of the olefin-based rubber (I) and hydrogenated block copolymer (II) [(I)/(II)] is 90/10 to 10/90 (mass ratio). With respect to a total of 100 parts by mass of the olefin-based rubber (I) and the hydrogenated block copolymer (II), the content of the polyolefin-based resin (III) is 10 to 200 parts by mass, and the content of the softening agent (IV) is 15 to 300 parts by mass. The hydrogenated block copolymer (II) comprises: a polymer block (A), primarily comprising structural units derived from an aromatic vinyl compound; and a polymer block (B) primarily comprising structural units derived from at least one substance selected from the group consisting of isoprene and butadiene, in which the total content of 3,4-bond units and 1,2-bond units is 45% or more. The peak top molecular weight of the hydrogenated block copolymer (II) is 50,000 to 200,000, and 70 mol% or more of the carbon-carbon double bonds in the polymer block (B) are hydrogenated.