A one-volume manga about a pair of friends on a mountain climbing trip who wind up trapped in a cabin when one is wounded, and one of the pair makes a frightening revelation...
From Baka-Updates:
Asai and Ishikura are old friends and fellow mountaineering enthusiasts who find themselves in an unfortunate situation when Ishikura injures his leg while on a mountain-climbing trip. They soon take refuge within a log cabin to await rescue from the heavy snowstorm that has stranded them.
But Asai’s greatest worry is not the forces of Nature that are raging around them, but the dark secret Ishikura revealed to him while gripped by fear of death -- and which has now made each man a liability to the other’s continued survival...