A system, of the present invention, for restraining a mouse includes: at least one home cage (10)； a passage (20) through which the mouse (60) moves, the passage (20) having at least one first open end (21a)； and a restraining device (50) which restrains the mouse by physically fixing the mouse (60), the at least one first open end of the passage (21a) being connected to the at least one home cage (10), the restraining device (50) being provided at a location on the passage (20) which location is different from the at least one first open end (21a) of the passage (20).
