(Proposal ID) S15B-125 (PI) Kawai, Nobuyuki (Proposal Title) Subaru Observations of Gamma-Ray Burst Afterglows (Abstract) We propose to conduct rapid "Target of Opportunity" observations of gamma-ray burst (GRB) afterglows using the prompt alerts from the {Swift}, INTEGRAL, {Fermi} satellites and MAXI to pursue following goals: (1) Detect and identify GRBs in the re-ionization era (6