Folding seat and seating system having folding seat

A seating system having a floor surface, stepwise decks each having a front end and a rear end, and a seat, said stepwise decks having a plurality of upper surfaces, wherein each said upper surface is positioned at a different height from said floor surface, said upper surfaces adjacent to each other and having height being increased accordingly as advancing from the front end of each of said stepwise decks to the rear end of each of said stepwise decks, and said seat positioned on said upper surfaces of said stepwise decks, said seat comprising:

• a first frame mounted on each of said upper surfaces of said stepwise decks, said first frame rotatable between a raised position where said first frame is raised from said upper surfaces and a horizontally laid position where said first frame is laid along said upper surfaces;
• a seat cushion supposed by said first frame, said seat cushion rotatable between a horizontal position where said seat cushion is horizontally extended from said first frame, when said first frame is rotated to said raised position, and a storage position where said seat cushion is raised along said first frame rotated to said raised position;
• a second frame mounted on each of said upper surfaces of said stepwise decks at a back of said first frame, said second frame rotatable between a raised position where said second frame is raised from said upper surfaces and a horizontally laid position where said second frame is laid along said upper surfaces, said second frame having a rear panel, said rear panel raised at a position adjacent to a front end of said upper surfaces and positioned upwardly from said upper surfaces when said second frame is rotated to the raised position, and said rear panel having an upper end projected upwardly from said upper surface positioned at the back of said first frame;
• an arm rest stretched between said first and said second frames, said arm rest rotatably connected to said first frame through a first pivot shaft, said arm rest rotatably connected to said second frame through a second pivot shaft, and said first and second frames interlocked to each other through said arm rest;
• a back rest rotatably supported on said second frame through said second pivot shaft, said back rest extending upwardly from the upper end of said, rear panel when said second frame is rotated to said raised position, and said back rest is inclined to a front of said rear panel;
• and
• a link member stretched between said back rest and said first frame, said link member having one end rotatably connected to said back rest and other end rotatably connected to said first frame, and said link member rotating said back rest to be parallel to said rear panel when said first and second frames are rotated from the raised position to the horizontally laid position.