Otogirisou: Hypericum Perforatum

One summer evening, a young man and a woman were driving down a winding mountain road. You take the role of the young man. The young woman is named Nami. The two of you attend the same college. While driving back home from an out-of-town date, you got into an accident. The car's brakes suddenly stopped working, leaving the car totaled and the two of you clueless about where to go, until you spotted the mailbox of a nearby home. Together, you trudged through the woods, struck by the rain and trembling from the lightning. Nami was looking more and more displeased. Emerging from the woods, you found an old western-style mansion gated off with high walls.

[From the original manual, translated by Tom]