[en] NOBORU, NeutrOn Beam line for Observation and Research Use, has been constructed in the Materials and Life Science Facility (MLF) of Japan Proton Accelerator Research Complex (J-PARC). NOBORU is designed to 'observe' a 1 MW Japan Spallation Neutron Source (JSNS), i.e., to study the neutronic performance of JSNS. The aim of experiments to be done with NOBORU is to contribute to stable operation, design validation, and integrity checking of JSNS. NOBORU will be used for 'research' activities also, i.e., as a test port for R and D activities and trial users who have new ideas. These devices will make possible ambitious experiments in the next decade. In this paper, the design and application of NOBORU are described, and its expected performance is investigated by Monte Carlo simulations