Novel x Gaming x Nihonbashi: Mitsui Fudosan and DeNA Co-host Immersive AR Mystery Event 'Chikai no Tomoshibi' Using 'Alplat' App
Mitsui Fudosan and DeNA have launched an immersive mystery event in Nihonbashi, Tokyo, utilizing the AR app 'Alplat'. Collaborating with Keigo Higashino's famous 'Kaga Kyoichiro series,' the event blends digital storytelling with real-world city exploration to revitalize the historic district.
📋 Article Processing Timeline
- 📰 Published: April 27, 2026 at 22:00
- 🔍 Collected: April 27, 2026 at 13:31
- 🤖 AI Analyzed: April 28, 2026 at 02:28 (12h 56m after Collected)
Mitsui Fudosan Co., Ltd. and DeNA Co., Ltd. are hosting 'The Nihonbashi Immersive Mystery: Chikai no Tomoshibi' (The Vow's Light), an interactive mystery event using the AR (Augmented Reality) app 'Alplat,' from April 27, 2026, to March 30, 2027, in Nihonbashi, Tokyo.
### About Alplat
'Alplat' is an experiential circulation event app developed and operated by DeNA that fuses location information with AR technology. It provides a new entertainment experience where the real world and digital stories intersect through actual city walking. With the concept of regional revitalization and rediscovering the charm of the city, it develops various contents such as circulation-type mysteries on a single platform.
### Background of the Event Planning
Mitsui Fudosan is working to create new vibrancy in Nihonbashi, its birthplace, by combining urban development and entertainment in collaboration with public, private, and regional sectors. This time, in partnership with DeNA, they have developed an event within the 'Alplat' app that allows visitors to enjoy a narrative experience while touring the streets of Nihonbashi. Through mechanisms where walking itself becomes an 'experience' set against historical streetscapes and shops, the project aims to promote circulation, improve the stay value for visitors, and communicate the district's appeal.
DeNA, based on expertise cultivated in the internet domain, operates businesses in entertainment areas such as games, anime, and IP content, as well as urban development areas like sports and smart cities. Through these multifaceted business operations, they have built strengths in implementing digital technology and developed unique revenue models and solutions.
This project leverages the strengths and assets of both Mitsui Fudosan and DeNA to revitalize the Nihonbashi area and rediscover its charm through a 'Urban Development x Entertainment' approach.
### City Walking x Mystery Mystery Using AR App
This event is held as a limited-time event within 'Alplat,' where users can experience a mystery set in Nihonbashi while walking around. To solve the mystery of an incident in Nihonbashi, participants visit landmarks to obtain scenarios, read the story, and explore the surroundings. Using AR technology through a smartphone camera and location services, it provides an immersive experience where the fictional world links with real streetscapes.
### Collaboration Story with Keigo Higashino's 'Kaga Kyoichiro Series'
The event features an original fictional story where players touch upon the charm of the Nihonbashi area while solving mysteries. Furthermore, in collaboration with the mystery novel series 'Kaga Kyoichiro Series' (by Keigo Higashino), which includes works like 'The Newcomer' and 'The Wings of the Kirin' set in Nihonbashi, the character Kaga Kyoichiro appears in the original story.
#### Introduction
A body found in Nihonbashi. Was it a crime or an accident? Left in hand was a single photograph of strangers and a small number. To find the truth, the protagonist visits Nihonbashi. Waiting there was an encounter with detective Kaga Kyoichiro and various human relationships surrounding the uncle. A 'drowned body' found on land—why did he die there?
### Event Overview
- **Title:** The Nihonbashi Immersive Mystery - Chikai no Tomoshibi -
- **Period:** April 27, 2026 (Mon) to March 30, 2027 (Tue)
- **Location:** Nihonbashi Muromachi Area (Chuo-ku, Tokyo)
- **Content:** Immersive mystery event using the AR app 'Alplat' (estimated time to clear: 3-5 hours)
- **Special Site:** https://lp.arplat.jp/chikai/
### About Alplat
'Alplat' is an experiential circulation event app developed and operated by DeNA that fuses location information with AR technology. It provides a new entertainment experience where the real world and digital stories intersect through actual city walking. With the concept of regional revitalization and rediscovering the charm of the city, it develops various contents such as circulation-type mysteries on a single platform.
### Background of the Event Planning
Mitsui Fudosan is working to create new vibrancy in Nihonbashi, its birthplace, by combining urban development and entertainment in collaboration with public, private, and regional sectors. This time, in partnership with DeNA, they have developed an event within the 'Alplat' app that allows visitors to enjoy a narrative experience while touring the streets of Nihonbashi. Through mechanisms where walking itself becomes an 'experience' set against historical streetscapes and shops, the project aims to promote circulation, improve the stay value for visitors, and communicate the district's appeal.
DeNA, based on expertise cultivated in the internet domain, operates businesses in entertainment areas such as games, anime, and IP content, as well as urban development areas like sports and smart cities. Through these multifaceted business operations, they have built strengths in implementing digital technology and developed unique revenue models and solutions.
This project leverages the strengths and assets of both Mitsui Fudosan and DeNA to revitalize the Nihonbashi area and rediscover its charm through a 'Urban Development x Entertainment' approach.
### City Walking x Mystery Mystery Using AR App
This event is held as a limited-time event within 'Alplat,' where users can experience a mystery set in Nihonbashi while walking around. To solve the mystery of an incident in Nihonbashi, participants visit landmarks to obtain scenarios, read the story, and explore the surroundings. Using AR technology through a smartphone camera and location services, it provides an immersive experience where the fictional world links with real streetscapes.
### Collaboration Story with Keigo Higashino's 'Kaga Kyoichiro Series'
The event features an original fictional story where players touch upon the charm of the Nihonbashi area while solving mysteries. Furthermore, in collaboration with the mystery novel series 'Kaga Kyoichiro Series' (by Keigo Higashino), which includes works like 'The Newcomer' and 'The Wings of the Kirin' set in Nihonbashi, the character Kaga Kyoichiro appears in the original story.
#### Introduction
A body found in Nihonbashi. Was it a crime or an accident? Left in hand was a single photograph of strangers and a small number. To find the truth, the protagonist visits Nihonbashi. Waiting there was an encounter with detective Kaga Kyoichiro and various human relationships surrounding the uncle. A 'drowned body' found on land—why did he die there?
### Event Overview
- **Title:** The Nihonbashi Immersive Mystery - Chikai no Tomoshibi -
- **Period:** April 27, 2026 (Mon) to March 30, 2027 (Tue)
- **Location:** Nihonbashi Muromachi Area (Chuo-ku, Tokyo)
- **Content:** Immersive mystery event using the AR app 'Alplat' (estimated time to clear: 3-5 hours)
- **Special Site:** https://lp.arplat.jp/chikai/