Medium protection device and medium separating and stacking device

A medium separating and stacking device comprising:

• a space in which a paper sheet shaped medium is stacked;
• a conveyance guide that is in communication with the space and that forms a conveyance path of the medium;
• a central shaft that is substantially orthogonal to a direction of progress of the medium along the conveyance path, that is substantially parallel to a face of the medium conveyed on the conveyance path, and that is separated by a predetermined distance from a location on the conveyance guide furthest to the conveyance path side;
• a tongue piece roller including a central body that has a radius from the central shaft of less than the predetermined distance and that rotates about the central shaft, and one, or two or more, flexible tongue pieces that are provided projecting out from the central body within a predetermined provision range of an outer circumferential portion centered on the central shaft;
• a through hole formed in the conveyance guide at a portion through which the tongue pieces pass during rotation of the central body about the central shaft;
• and
• a guide body that is provided in a non-provision range excluding the provision range of the outer circumferential portion of the central body centered on the central shaft, and that is positioned further outward than the outer circumferential portion.