A storage case includes a frame, a top plate, and a drawer. The frame includes a bottom plate, side plates, and a rear plate. The top plate covers the upper side of the frame. The drawer is freely pulled out of and pushed into the frame through an open front side of the frame. The side plates of the frame are foldable between an upright position, at which the side plates extend upright from left and right sides of the bottom plate, and a folded position, at which the plates extend along an upper surface of the bottom plate. The rear plate is foldable between an upright position, at which the rear plate extends upright from a rear side of the bottom plate, and a folded position, at which the rear plate extends along a lower surface of the bottom plate.

A foldable file box includes: a plastic sheet including a bottom wall and two side walls that are foldable relative to the bottom wall to form a U-shaped structure; two side frames interlocking with the bottom wall and the two side walls to form a box structure including a top opening; two hanging rods each including a bottom portion interlocking with the top part of the plastic sheet, and two ends of each hanging rod respectively interlocking with the two side frames; and a top cover interlocking with the two side frames and the two hanging rods to close the top opening.

A container assembly including a number of sidewall assemblies is provided. Each sidewall assembly includes a number of sidewalls. Each sidewall includes a generally planar perimeter and a number of tapered edge segments. The sidewalls are disposed in an enclosing configuration wherein a number of the tapered edge segments overlap. The sidewalls define a generally enclosed space. Further, each overlapping tapered edge segment is coupled to an adjacent overlapping tapered edge segment.

A foldable file box includes: a plastic sheet including a bottom wall and two side walls that are foldable relative to the bottom wall to form a U-shaped structure; two side frames interlocking with the bottom wall and the two side walls to form a box structure including a top opening; two hanging rods each including a bottom portion interlocking with the top part of the plastic sheet, and two ends of each hanging rod respectively interlocking with the two side frames; and a top cover interlocking with the two side frames and the two hanging rods to close the top opening.