Chair and seat support mechanism

A chair comprising:

• a leg erected on a floor surface;
• a seat arranged in a predetermined reference position above the leg;
• and
• a support mechanism interposed between the leg and the seat, wherein
• the support mechanism is arranged below the seat, and is configured to movably support the seat along a predetermined trajectory, the support mechanism comprises:
• an omnidirectional connection unit configured to operably connect the seat to the leg such that the seat moves from the predetermined reference position in a moving direction including the front-rear direction and the left-right direction with respect to the leg;
• and
• a seat inclining function configured to downwardly incline a tip side towards the movement direction of the seat;
• and
• a return-force generation mechanism configured to generate, by elevating a center of gravity of the seat in accordance with the operation of the seat from the predetermined reference position, in accordance with an amount of movement, a return force in a direction of returning the seat to the predetermined reference position.