In line with the game by Cocktail Soft.

Collin, a rather noble but ordinary man - finds himself lured to a cave by the dream in which a beautiful girl named Feelia appeared before him. Whilst he was warned off through the elder of his village, he still feels drawn in... and with the arrival of your beautiful adventurer, and merely a trace of seduction... in he shall go.

But what is in wait? And just what from the mysterious girl who gave the impression to Collin in the dream?