Engaged to the Unidentified Special

After participating in a lucky draw, Hakuya Mitsumine wins first prize: tickets for a trip to a hot spring of his choice. Hakuya's sister, Mashiro, wishes to visit a specific hot spring in a village surrounded by intriguing rumors about alleged sightings of mysterious creatures in its area. Supportive of his sister's pick, Hakuya, along with Mashiro and a few friends, heads to the village.

When the group ventures into a dark forest determined to catch a glimpse of the creatures, their pursuit is instead hindered by multiple uncanny mishaps. Strayed from what was supposed to be a simple goal, the group is determined to find the creatures or else they will return home with their curiosity dissatisfied.