"Kagami no Tokushu Shonen Kosei Shisetsu" Reaches 100 Million Accesses! Over 1.5 Million Players, Second Anniversary Project Kicks Off
Fourth Dimension's ARG "Kagami no Tokushu Shonen Kosei Shisetsu" celebrates its second anniversary with over 100 million accesses and 1.5 million players, launching a project including a 50% OFF sale, comic adaptation, pop-up shops, and LINE stickers.
📋 Article Processing Timeline
- 📰 Published: April 1, 2026 at 20:36
- 🔍 Collected: April 1, 2026 at 16:47
- 🤖 AI Analyzed: April 17, 2026 at 13:28 (380h 40m after Collected)
Fourth Dimension, a creator group specializing in ARG, announces that "Kagami no Tokushu Shonen Kosei Shisetsu" (Mirror's Special Juvenile Reformatory) has surpassed 100 million accesses and 1.5 million players in its second year, marking its second anniversary.
To commemorate this, in addition to a half-price sale on related products, pop-up stores called "Rehabilitation Work Product Exhibition and Sale" will be held in Tokyo and Osaka. Furthermore, various second-anniversary projects, including new comic adaptations and LINE sticker releases, will be launched sequentially.
"Kagami no Tokushu Shonen Kosei Shisetsu" was released on April 1, 2024, as an experiential mockumentary game. Initially, it gained attention as a high-difficulty game with a completion rate of only 6%. Since then, the number of players has continued to grow, establishing ARG as a genre of web-exploration games.
■ 50% OFF Sale
From April 1st to 7th (Shinadori Day), the following products will be sold at a record-breaking 50% off at the Fourth Dimension Online Shop.
・Shinadori Plushie: ¥3,300 ⇒ ¥1,650
・Official Setting Material Pamphlet: ¥2,200 ⇒ ¥1,100
・Reiwa 6th Year Facility Guidebook: ¥2,200 ⇒ ¥1,100
・Reiwa 7th Year Facility Guidebook: ¥2,200 ⇒ ¥1,100
*Digital versions can be purchased on Amazon.
■ Manga "Fictional Landscape"
"Fictional Landscape" (Art by Chita Nehanbin, Original Story by Meme Design, Concept & Supervision by Fourth Dimension), a comic adaptation depicting "Kagami no Tokushu Shonen Kosei Shisetsu" from a player's perspective, will begin serialization on various e-book distribution platforms from late May.
Starting from the actual websites players explored, the story follows Miko Ayano, a freelance occult writer, and her younger brother Toki, as they pursue "another truth" not told in the main game, unfolding a completely original narrative.
It should be noted that this work is not strictly a comic adaptation of "Kagami no Tokushu Shonen Kosei Shisetsu" itself, but rather a series investigating various ARGs. The first installment, which tackles mysterious incidents blurring the lines between reality and fiction, will be "Kagami no Tokushu Shonen Kosei Shisetsu."
■ Pop-up Store "Rehabilitation Work Product Exhibition and Sale"
Pop-up stores for "Kagami no Tokushu Shonen Kosei Shisetsu" titled "Rehabilitation Work Product Exhibition and Sale" will be held in Tokyo from late May to early June, and in Osaka from late June to early July.
Various new goods are planned for the pop-up stores, and the "Reiwa 8th Year Facility Guidebook," which offers an additional story for "Kagami no Tokushu Shonen Kosei Shisetsu," is also scheduled for sale.
Please stay tuned for further details on the event schedule.
"I've Been to Kagami no Tokushu Shonen Kosei Shisetsu" Cookies
Cookies that were previously sold exclusively at the "Kagami no Tokushu Shonen Kosei Shisetsu" store will now also be available at the pop-up stores.
Happiness Cultivation Drug "Hapihapinal"
A ramune-flavored trial drug used within the "Kagami no Tokushu Shonen Kosei Shisetsu" facility has partially leaked and will be sold exclusively at the pop-up stores.
Inmate Issued "Curry Plate & Spoon"
A "just-the-right-size" curry plate and spoon set, issued to inmates upon admission, will be specially distributed. Eat curry with this set and feel like an inmate starting today.
Shinadori Bang Clip
■ New LINE Sticker Sales
Following "Shinadori STAMP," two new types of LINE stickers related to "Kagami no Tokushu Shonen Kosei Shisetsu" have been released.
Bicolor Moon
Stickers featuring carefully selected impressive scenes from the manga "Bicolor Moon."
Sales: https://store.line.me/stickershop/product/32676429/ja
Dr. Okabe LINE Stickers
Stickers depicting the busy yet relaxed daily life of Dr. Okabe, who works diligently at the reformatory.
In addition to the projects mentioned above, a TRPG version of "Kagami no Tokushu Shonen Kosei Shisetsu" is also awaiting release, with information to be disclosed at a later date.
Sales: https://store.line.me/stickershop/product/32619527/ja
■ Fourth Dimension
Fourth Dimension is a creator group that weaves stories in the ambiguous realm between reality and virtuality.
・Official Website: https://www.daiyonkyokai.net/
・X: https://x.com/daiyonkyokai
・Store: https://shop.daiyonkyokai.net/
・Discord: https://discor
To commemorate this, in addition to a half-price sale on related products, pop-up stores called "Rehabilitation Work Product Exhibition and Sale" will be held in Tokyo and Osaka. Furthermore, various second-anniversary projects, including new comic adaptations and LINE sticker releases, will be launched sequentially.
"Kagami no Tokushu Shonen Kosei Shisetsu" was released on April 1, 2024, as an experiential mockumentary game. Initially, it gained attention as a high-difficulty game with a completion rate of only 6%. Since then, the number of players has continued to grow, establishing ARG as a genre of web-exploration games.
■ 50% OFF Sale
From April 1st to 7th (Shinadori Day), the following products will be sold at a record-breaking 50% off at the Fourth Dimension Online Shop.
・Shinadori Plushie: ¥3,300 ⇒ ¥1,650
・Official Setting Material Pamphlet: ¥2,200 ⇒ ¥1,100
・Reiwa 6th Year Facility Guidebook: ¥2,200 ⇒ ¥1,100
・Reiwa 7th Year Facility Guidebook: ¥2,200 ⇒ ¥1,100
*Digital versions can be purchased on Amazon.
■ Manga "Fictional Landscape"
"Fictional Landscape" (Art by Chita Nehanbin, Original Story by Meme Design, Concept & Supervision by Fourth Dimension), a comic adaptation depicting "Kagami no Tokushu Shonen Kosei Shisetsu" from a player's perspective, will begin serialization on various e-book distribution platforms from late May.
Starting from the actual websites players explored, the story follows Miko Ayano, a freelance occult writer, and her younger brother Toki, as they pursue "another truth" not told in the main game, unfolding a completely original narrative.
It should be noted that this work is not strictly a comic adaptation of "Kagami no Tokushu Shonen Kosei Shisetsu" itself, but rather a series investigating various ARGs. The first installment, which tackles mysterious incidents blurring the lines between reality and fiction, will be "Kagami no Tokushu Shonen Kosei Shisetsu."
■ Pop-up Store "Rehabilitation Work Product Exhibition and Sale"
Pop-up stores for "Kagami no Tokushu Shonen Kosei Shisetsu" titled "Rehabilitation Work Product Exhibition and Sale" will be held in Tokyo from late May to early June, and in Osaka from late June to early July.
Various new goods are planned for the pop-up stores, and the "Reiwa 8th Year Facility Guidebook," which offers an additional story for "Kagami no Tokushu Shonen Kosei Shisetsu," is also scheduled for sale.
Please stay tuned for further details on the event schedule.
"I've Been to Kagami no Tokushu Shonen Kosei Shisetsu" Cookies
Cookies that were previously sold exclusively at the "Kagami no Tokushu Shonen Kosei Shisetsu" store will now also be available at the pop-up stores.
Happiness Cultivation Drug "Hapihapinal"
A ramune-flavored trial drug used within the "Kagami no Tokushu Shonen Kosei Shisetsu" facility has partially leaked and will be sold exclusively at the pop-up stores.
Inmate Issued "Curry Plate & Spoon"
A "just-the-right-size" curry plate and spoon set, issued to inmates upon admission, will be specially distributed. Eat curry with this set and feel like an inmate starting today.
Shinadori Bang Clip
■ New LINE Sticker Sales
Following "Shinadori STAMP," two new types of LINE stickers related to "Kagami no Tokushu Shonen Kosei Shisetsu" have been released.
Bicolor Moon
Stickers featuring carefully selected impressive scenes from the manga "Bicolor Moon."
Sales: https://store.line.me/stickershop/product/32676429/ja
Dr. Okabe LINE Stickers
Stickers depicting the busy yet relaxed daily life of Dr. Okabe, who works diligently at the reformatory.
In addition to the projects mentioned above, a TRPG version of "Kagami no Tokushu Shonen Kosei Shisetsu" is also awaiting release, with information to be disclosed at a later date.
Sales: https://store.line.me/stickershop/product/32619527/ja
■ Fourth Dimension
Fourth Dimension is a creator group that weaves stories in the ambiguous realm between reality and virtuality.
・Official Website: https://www.daiyonkyokai.net/
・X: https://x.com/daiyonkyokai
・Store: https://shop.daiyonkyokai.net/
・Discord: https://discor
FAQ
What does the second-anniversary project for "Kagami no Tokushu Shonen Kosei Shisetsu" include?
It includes a 50% OFF sale, a comic adaptation, pop-up stores, and LINE sticker sales. A TRPG version is also planned for future release.
Where will the pop-up stores be held?
They are scheduled for Tokyo from late May to early June, and Osaka from late June to early July. New merchandise and an additional story guidebook will also be sold.
What is the manga "Fictional Landscape" about?
It's an original story depicting "Kagami no Tokushu Shonen Kosei Shisetsu" from a player's perspective, pursuing "another truth" not revealed in the main game.