Tokyo Discovery City 2025 is being held at the Tokyo Dome. This is the "Mystery of the Midday Sun," a take-home puzzle kit sold only at the venue. I believe it's valuable because it's only available on weekends and holidays with a prior reservation. I am selling it because I have opened it once and solved the puzzles. There are signs of opening on the envelope, but the contents were put back in the envelope immediately after taking photos, so they are almost unused. Although opened, there are no writings or use of the accessories needed to solve the puzzles. There are no missing accessories. I believe you will be able to solve the puzzles without any problems.