Trailer House Mystery Launches at Nagai Uminote Park Soleil no Oka in Yokosuka, Kanagawa from March 1, 2026

Starting March 1, 2026, guests staying at the trailer house cabins of Nagai Uminote Park Soleil no Oka (ソレイユの丘) in Yokosuka, Kanagawa, can take part in a brand-new immersive mystery experience called Trailer House Mystery. The experience is a collaboration between Hibiya Kadan, Areano, and KAGENAZO (operated by FUN SPIRITS), blending overnight accommodation with story-driven puzzle solving.

About Trailer House Mystery

Trailer House Mystery places guests at the center of a mystery that unfolds within their trailer house cabin. Each participant receives a single enigmatic clue upon check-in, which draws them into the story of a family and the secrets hidden in their memories. The surrounding natural environment — the sea view, the trees, the sounds of the park — becomes part of the storytelling itself.

Rather than a standalone attraction, the experience is designed so that the stay itself becomes the narrative. Guests progress through the mystery at their own pace during their overnight visit, spending approximately one hour solving the puzzle.

Event Details

• Content name: Trailer House Mystery
• Start date: March 1, 2026 (Sunday) onward
• Price: Free (trailer house accommodation charged separately)
• Duration: Approximately 1 hour
• Venue: Nagai Uminote Park Soleil no Oka — Trailer House Area (4-chome, Nagai, Yokosuka, Kanagawa)
• Format: In-room mystery experience for overnight guests

How to participate:

1. Book a trailer house stay via the official Soleil no Oka website.
2. Pick up the Trailer House Mystery kit at the front desk on the day of arrival.
3. Dive into the mystery from inside your trailer house cabin.

About Nagai Uminote Park Soleil no Oka

Set along the shores of Sagami Bay in Yokosuka, Nagai Uminote Park Soleil no Oka is a large experiential park offering something for every type of visitor. The grounds include seasonal flower fields, athletic zones, animal interaction areas, camping, glamping, and trailer house accommodations, as well as restaurants and a market.

Following a 2023 renewal, the park has been expanding its concept of "an entertainment park where anyone can play and enjoy to their heart's content, 365 days a year," integrating nature, food, activities, and lodging into a single destination.

• Official website: https://soleil-park.jp/
• Official Instagram: https://www.instagram.com/soleil_yokosuka/
• Official X: https://x.com/soleil_yokosuka

Trailer House Facilities

The trailer houses at Soleil no Oka come in two styles: the "Ocean Cabin," positioned with views of the sea, and the "Forest Cabin," nestled in the surrounding greenery.

• Check-in: 1:00 PM to 5:00 PM
• Check-out: 10:00 AM
• Interior: Tatami-style flooring with air conditioning
• Ocean Cabin: 12 rooms (approximately 13 m²)
• Forest Cabin: 8 rooms (approximately 19 m², pet-friendly)
• Price: From ¥18,700 (tax included), varies by room type

Reservations can be made via the official website:
Trailer Cabin Booking Page (Official)

Also Running: Soleil STORY

Alongside Trailer House Mystery, the park is also hosting Soleil STORY, a walk-around mystery event that has been running since December 24, 2025. Participants explore the park grounds while following a story and solving puzzles along the way.

• Participation fee: ¥2,750 (tax included)
• Duration: Approximately 180 minutes

The two experiences complement each other, with Soleil STORY offering a daytime exploration activity and Trailer House Mystery providing an after-dark, in-room adventure for overnight guests.