2009’s Dendera is a standalone novel by Yuya Sato. The 2015 Haikasoru translation is by Nathan A. Collins and Edwin Hawkes.
Every inhabitant of the Village who manages to make it to age seventy (despite a life of hard labor, disease, and famine) is rewarded by exile to the Mountain (in winter) where, they are told, they can expect a quick death and Paradise thereafter.
Eager for Paradise, Kayu Saito cheerfully heads up the mountain. She is outraged not to find her Elysium.