Keio vs Odakyu Railway Mystery Challenge 2026: 44 Stations, Routes & Prizes
Keio vs Odakyu Ensen Ai Battle is a free mystery-solving event running from September 14 through November 30, 2026 across 44 stations on the Keio and Odakyu networks. Participants choose either the Keio or Odakyu team, solve station-based puzzles, and earn points for their chosen side.
At a glance
| Dates | September 14-November 30, 2026 |
|---|---|
| Participation fee | Free; transport and mobile data costs are not included |
| Area | 44 stations across the Keio and Odakyu networks |
| Long course | About 5-7 hours; booklet required |
| Quick course | From about 10 minutes per station; no booklet required |
| What you need | A smartphone or tablet with internet access; LINE is used for some puzzle functions |
How to join
- Open the official event website and register through the event system.
- Choose either the Keio team or the Odakyu team.
- Select the longer walking course or the quick one-station course.
- Travel to the participating stations and solve the puzzles shown in the booklet or on the website.
You can challenge puzzles on both railway networks regardless of which team you join. Points earned from completed puzzles are added to the team selected at registration.
Two ways to play
The long walking course starts from Shinjuku and takes participants through 12 stations on each railway. The organizer gives an estimated completion time of 5-7 hours, so an early start is practical if you want to complete a route in one day.
The quick course can be played one station at a time and is designed to take from around 10 minutes per station. It is easier to combine with shopping, commuting or sightseeing.
Quick-course stations
Keio: Hatsudai, Sakurajosui, Tobitakyu, Fuchu-keiba-seimon-mae, Seiseki-sakuragaoka, Tama-Dobutsukoen, Takao, Minami-osawa, Hashimoto and Kugayama.
Odakyu: Yoyogi-uehara, Mukogaoka-yuen, Shin-yurigaoka, Machida, Ebina, Isehara, Hadano, Yamato, Shonandai and Haruhino.
Prizes
Participants who meet the conditions for each prize category can enter drawings for railway- and area-related rewards. The Japanese event site lists prizes including department-store gift certificates, attraction tickets, hot-spring tickets and railway museum packages. Eligibility differs by course and achievement, so check the official prize conditions before entering.
Transport costs
The event itself is free, but you pay normal rail fares. If you plan to get on and off trains many times in one day, compare regular fares with the railway companies’ one-day passes before you start. A short one- or two-station route may still be cheaper with ordinary tickets.
Important rules
- Do not walk while looking at your phone on station platforms or in busy public areas.
- Do not ask station staff or nearby businesses for puzzle answers or hints.
- Do not post puzzle answers on social media.
- Booklets are available only while supplies last.
- Check the official website before traveling for the latest operating information.