"Doll's Liminal" is a first-person exploration survival horror game set in a remote region of Japan. In the area known as "Doll's Liminal," an experiment called "Freight Transport Test" is conducted to see if one can pass through the area and reach the other side safely. The unit for measuring the depth of space is called "Depths," and the strange phenomenon of Japan, the "Doll's Liminal," attempts to take those who enter it to the deepest layer of "Depths 399."