Top left: illustration of the proposed physical scenario with a planet orbiting at ∼100 au (Section 4.3). Top right: gas column density of our radiation-hydrodynamic simulation (Section 5). Bottom: synthetic 1.65 μm scattered-light image at the full resolution (left) and convolved with the HiCIAO point-spread function (middle), and the observed HiCIAO image (right).