They were told to not fear death to protect the mountain. But the mountain won't die for them. What they saw beyond the path where humans disappeared was---
In the future after humanity has declined, a human child becomes the subject of a certain beastman's research... A serious 32 page standalone manga story featuring their meeting and parting.
Kasumi gets lost in the shrine near the school on her way home, and a mysterious girl's power makes her unable to descend the mountain. Can the two return home safely? Who is the mysterious girl?