Seat belt for vehicle

A seat belt for an occupant sitting on a seat including a seat back in a vehicle, the seat belt comprising:

• a tongue part provided at a first side portion of the seat, the tongue part including at least one first guide part that is operable between extended and contracted configurations, and at least one first webbing with a tongue wound therein, wherein the tongue of the first webbing is connected with an end portion of the first guide part so that the first webbing is extended together when the first guide part is extended;
• and
• a buckle part provided at a second side portion of the seat, the buckle part including a second guide part that is operable between extended and contracted configurations, and a second webbing with a buckle is wound therein, wherein the buckle of the second webbing is connected with an end portion of the second guide part so that the second webbing is extended together when the second guide part is extended,
• wherein:
• the tongue of the tongue part is fastened to the buckle of the buckle part,
• the tongue of the tongue part is hung on the end portion of the first guide part so that the tongue of the tongue part is moved together with the end portion of the first guide part when the first guide part is extended, whereby the first webbing is extended, and
• the tongue is separated from the first guide part when the first guide part is contracted after the tongue is fastened to the buckle, so that the first webbing is not contracted but only the first guide part is contracted.