Provided is a composition including: an acrylamide compound represented by general formula (1) in 20% by mass or greater but 50% by mass or less; a multifunctional monomer in 40% by mass or greater but 70% by mass or less; and a polymerization initiator,where in general formula (1), R1 represents alkyl group containing 1 through 6 carbon atoms, X represents alkylene group containing 1 through 6 carbon atoms, and Y represents any one selected from the group consisting of general formula (2) below and general formula (3) below,where in general formula (2), R2 represents alkyl group containing 1 through 10 carbon atoms, and * represents binding site with X above,where in general formula (3), R2 represents alkyl group containing 1 through 10 carbon atoms, and * represents binding site with X above.