Disclosed herein is an apparatus for rear seat detection. The apparatus may include: an indoor camera configured to provide image data; an indoor radar configured to provide radar data; a controller including a first processor and a second processor. The first processor configured to obtain information on a change in a front passenger seat and a rear seat of a vehicle based on processing the image data. The second processor configured to obtain motion information on an object in the rear seat of the vehicle based on processing the radar data. The first controller may identify a change of a detection area in the rear seat, and determine whether a human is seated in the rear seat of the vehicle.

A condition correction unit includes a plan storage unit configured to store correction plans showing contents of correction of the body condition of a seated person, a presentation unit configured to read a correction plan based on a current value measured by a measurement unit from the plan storage unit and present the correction plan to the seated person, and a processing execution unit configured to execute processing to correct posture by controlling an operating unit. The plan storage unit stores the correction plan presented by the presentation unit in association with information identifying the seated person when the correction plan is presented. The processing execution unit reads the correction plan associated with the information identifying the seated person from the plan storage unit, and executes the processing to correct the posture according to correction contents shown by the correction plan.