Showcasing 200+ Obsession-Driven Items with Exhibitions, Interactive Experiences, and a Limited Flea Market by High School Artist MON7A
Mercari, Inc. will host "Hennnafleamarket," an experiential flea market event, at OPENBASE SHIBUYA in Tokyo's Shibuya district from February 27 (Friday) to March 1 (Sunday), 2026, for three days. The event will feature approximately 200 "obsession items" curated by passionate collectors. In commemoration of the event, current high school student artist MON7A will hold a limited flea market, alongside participatory immersive experiences where visitors can view, experience, and purchase unique items. With a combination of exhibition, experience, and purchase opportunities, the event aims to create new connections with items that are "loved too much by someone" and difficult to find through search algorithms. The event defines "Hennn" (strange/unusual) not as conventional eccentricity or weirdness, but as a form of "love" born from someone's excessive passion for specific items or genres.
Special website: https://jp-news.mercari.com/hennnafleamarket/
1F Hennn Museum
Outdoor Exhibition
Background of "Hennnafleamarket"
Within Mercari's marketplace, there exist numerous niche communities where items are continuously traded by people who deeply love specific genres, despite having smaller transaction volumes. Examples include "kokeshi dolls" where each piece has a different face, and "ugly sweaters" that become more endearing the uglier they are. In these communities, unique values and backgrounds such as "why someone wants this" and "why it's traded at this price" are shared, with the context written in product descriptions and sellers' sentiments influencing purchasing decisions.
According to a survey conducted by Mercari in February 2026※1, approximately 59% of respondents found efficient product searches through algorithm evolution "convenient," indicating that recommendation features as a starting point for purchasing experiences have created an environment where people can quickly reach desired items, significantly improving consumer convenience. However, when reflecting on recent shopping experiences, approximately 51% felt that "opportunities to encounter unexpected products and feel excitement have decreased," suggesting that while convenience has improved, opportunities for "unexpected discoveries" have diminished.
Even in this environment, approximately 57% responded that they "want to choose after knowing the background, culture, and maker's thoughts when purchasing items." Comments such as "I wasn't planning to buy it, but was moved while learning the background and ended up purchasing" were observed, suggesting that "obsession" is not limited to some enthusiasts but is a feeling that many people potentially seek. Given this background, Mercari planned the real-life event "Hennnafleamarket" with the theme of obsession, to provide a place that offers the value of "things outside algorithms" and serendipitous encounters.
※1: Mercari Lifestyle Survey Results (Respondents: 992, Survey Period: February 9 to 15, 2026)
"Hennnafleamarket" Overview
"Hennnafleamarket" reinterprets "Hennn" not as conventional eccentricity or weirdness, but as a form of "love" born from someone being "biasedly" too passionate about specific items or genres, offering an experiential flea market where visitors encounter items through exhibition, experience, and purchase. Survey results showed that approximately 1 in 3 people "have items they're particular about or attached to and want to talk about to someone"※1. Additionally, it was revealed that encounter triggers include "introductions from people," "accidental discoveries," and "in-store encounters," indicating that connection points outside algorithms exist to a certain extent.
Based on this background, the event is configured with three areas—"Hennn Museum," "Hennn Experience," and "Hennn Store"—to provide a real-life space for encountering "obsessions" that are difficult to find through search or recommendations. The event also features high school artist MON7A, who has gained support with their unique sensibility. MON7A will exhibit fashion items with "all-over patterns" that they love, and on the event's opening day, a limited flea market commemorating the event is planned.
Event Details
- Name: Mercari "Hennnafleamarket"
- Event Period: February 27, 2026 (Friday) 1:00 PM to 9:00 PM, February 28 (Saturday), March 1 (Sunday) 11:00 AM to 9:00 PM
- Location: OPENBASE SHIBUYA (14-13 Udagawa-cho, Shibuya-ku, Tokyo)
- Access: 8-minute walk from JR Shibuya Station Hachiko Exit
- Admission: Free
- Entry Method: No advance reservation required (except for MON7A's limited flea market)
※Entry restrictions or numbered tickets may be distributed during crowded times. - Special Benefit: Turn the gacha in the venue to randomly receive original design stickers themed on "Hennn items" that someone loved. ※Limited quantity
- Special Website: https://jp-news.mercari.com/hennnafleamarket/
How to Enjoy the Experiential Flea Market Event "Hennnafleamarket"—From Exhibitions to Experiences and Purchases
1. From Artists to Obsession Collectors: Diverse "Someone's Favorites" Gathered—Encounter and Discover New Perspectives
The venue features perspectives from current high school student artist MON7A, who enjoys immense popularity among young people, as well as eraser collectors, retro game collectors, and others who have deeply loved specific genres, introducing the background and value of items. Within Mercari, even items whose value is not easily visible in general markets have been discovered and traded through collectors' and enthusiasts' perspectives. This exhibition creates an experiential space for encountering someone's favorites, along with the obsession stories behind "why it was sold" and "why it was bought."
Planned Obsession Categories
Massive Guardians Quietly Supporting Daily Life: "Dams"
Dams that protect towns from heavy rain, nourish dry fields, and light up electricity through water circulation. However, behind their too-great significance, memories of villages submerged underwater and the sweat and tears of people who risked their lives are soaked in. Visiting dams is a "pilgrimage" to the stories carved into that land.
Tourist Attraction Magic: Souvenirs That Drive Reason Mad
"Why did I want that so much?" Enchanted by the magic of travel destination non-daily life, we bring back souvenirs today. Experience the loveliness that drives reason mad.
Who Decided What's Stylish? Obsession Closet Where Common Sense Bugs Out: "Fashion"
Quirky clothes that overturn the definition of "fashionable" gather. When you feel endearment after going full circle, you can no longer escape this swamp.
Small Love Found at Daily Life's Edge: "Bento"
"Isn't it a waste to throw this away?" That momentary heart flutter might be the beginning of obsession. Sharing the perspectives of collectors who poured love into side characters that everyone overlooks.
For Some, All Winners; For Others, All Losers: Drawing Hundreds of Yen Worth of Love: "Capsule Toys"
You don't know what you'll get. Still, or rather, that's why you keep turning "fate." In modern times where efficiency and time performance are emphasized, this irrationality itself is romance.
Justice Is What We Decided: "Gals"
In 1995, the legendary gal magazine "egg" was born. Without SNS or "Insta-worthy" moments, gal culture polished within the gaze of peers relying on magazines and streets created various items and cultures in the 2000s. Delivering fully-loaded gal love rekindled in the Reiwa era.
Obsession Collectors List (in alphabetical order by Japanese names)
- MON7A / All-over pattern items
- Misako Aoki / Lolita fashion
- Katsufumi Tokunaga / Vintage sneakers
- Fujita / Retro games
- Mayupu~ / Erasers
- Yoshinori Morishita / Rubber ducks
- Mero Yamashita / Heisei retro goods
- TRADMAN'S BONSAI team / Bonsai
2. Interactive Experiences Including "Take Photos with Real Gals!?" and "Kokeshi Face General Election"—Experience Unfamiliar Items
"Hennn Experience" features participatory experiences such as the "Gal Appearance Event" where real gals approach and sometimes take photos together, the "Kokeshi Face General Election" where you choose your favorite from kokeshi faces that seem identical at first glance, and "Find the Correct Remote Control!" where you search for the correct one among piles of remote controls. Through experiencing new perspectives not yet encountered, visitors can draw out new "interests" within themselves.
3. Flea Market Space Where Obsession Enthusiasts Gather, Experiencing "Actually Picking Up and Purchasing"—The Essence of Flea Markets
B1F Hennn Store
"Hennn Store" features specialty shops and stores that obsession enthusiasts have loved daily, gathering in one place to commemorate the event. This experiential project allows visitors to actually pick up, purchase, and take home obsession items born from someone's excessive love, along with their backgrounds.
Store List (in alphabetical order by Japanese names)
- Issen / Cactus specialty store
- Team Omoshiro Hojin Kayac / Volunteer employees' obsession goods
- Kamenya Omote / Mask specialty store
- Takada Kozo Shoten / Brush specialty store
- Ducks / Rubber duck specialty store
- Hayashi Goods Shop / Forest-related item goods
- Jimbocho Club / 80s-90s girls' culture (magazines and goods) specialty store
- 4BFC / Soccer items specialty store
- soma / Vintage sneaker specialty store
- TRADMAN'S BONSAI / Bonsai specialty store
4. Participatory Gacha Experience to Take Home "Hennn Items" Someone Loved
For visitors, a gacha experience is available where they can win original stickers themed on "Hennn items that someone loved." Using the special coin distributed at entry after touring exhibitions and experiences, it provides an opportunity for each visitor to reflect on the "obsession" that left an impression.
- "Hennnafleamarket" original stickers
- "Someone's 'interesting obsession'" print stickers
5. MON7A's Limited Flea Market Commemorating "Hennnafleamarket" Opening Confirmed!
On the opening day, current high school student artist MON7A, who is attracting attention, will hold a limited flea market directly introducing a total of 27 items to visitors. MON7A will bring personal items they've spent time with and discuss items with visitors, sharing backgrounds, episodes, and memories from when they were used for each piece.
Those wishing to participate require advance application, so please check the following URL for details.
Special website: https://jp-news.mercari.com/hennnafleamarket/
MON7A Profile
Born July 6, 2007, Tokyo-born current high school student artist MON7A (Monta). After appearing on a romantic reality show, gaining attention centered on Generation Z, made major debut in January 2026 with Universal Music/EMI Records. Now the most-watched new generation artist, ranking on various media trend rankings.
MON7A's Obsession Comment:
I also like simple clothes, but I always incorporate all-over pattern items into my outfits! I like patterns where the same pattern continues, and I also like where completely different patterns connect. When I wear all-over patterns, I feel wrapped in that pattern, which gives me security. When choosing clothes, I can find many ideas I wouldn't think of myself, so it's very fun. Rather than "I want to express!" what's inside me, it's a feeling of being armed with patterns and colors. Various eras' clothes feel like they're making me a bit stronger, so I love all-over patterns!
