The key information source is the page from acyyx.cc (source 9), which provides a description of the game. Another source is the doujineroero.blog.jp page (source 14), which also contains details. I should also use the Ci-en page (source 19) for context on the creator.
In this story, the protagonist, a man named Gonzō (権蔵), who is described as a perennial bachelor, eagerly anticipates this yearly event. His target is Shizuyo (静代), the most beautiful woman in the village. Shizuyo is married to a man named Sakichi (佐吉), but the narrative suggests he is sexually inadequate (床下手), leading the protagonist to believe she must be craving male attention. NTREX Yoru Yobai Mura Banashi -RJ01334689-