Shading system and roller unit for same

The shading system (20) has roller units (30,60) for shading discs (18a,18b) of side window (14) respectively. The flexible sheets (36,66) and rotatable winding shafts (34,64) are provided in roller units respectively. The flexible sheets of roller units are wound on winding shafts during storage state. The flexible sheets of roller units are unwound from winding shafts during functional state. The flexible sheets of roller units are manually transferred from storage state to functional state by applying external force at distal ends (38,40,68,70) of sheets respectively. Independent claims are included for the following: (1) side door; and (2) motor vehicle.