Nijisanji and Daiyonkyokai Launch ARG 'PARALLEL CASE: 2434' Case 01
This marks the first collaboration between Nijisanji and Daiyonkyokai, the ARG creator known for "Hito no Saifu," bringing the physical item-based storytelling format to a VTuber audience.
Key Facts
- The first installment of the collaboration ARG "PARALLEL CASE: 2434" between Nijisanji and Daiyonkyokai was released on August 21, 2026.
- The physical item "Mashiro's Ruins Exploration Pouch" is priced at 5,000 yen including tax and is available at the Nijisanji Official Store and the Daiyonkyokai Online Shop.
- EPISODE 01 of "CASE 01: Mashiro's Record" is free to play, while EPISODE 02 requires purchasing the pouch.
- Additional merchandise includes exploration sets for Mashiro, Kazune Kurusu, and Sister Claire at 4,400 yen each, clear files at 700 yen each, and an acrylic panel at 3,000 yen.
- The project is described as separate from Daiyonkyokai's previous works, depicting new stories that cycle through the seasons.
Reporting from 3 sources: 4Gamer.net, Denfaminicogamer, PANORA.
Nijisanji and the creator group Daiyonkyokai released the first installment of their collaboration ARG "PARALLEL CASE: 2434" on August 21, 2026. Titled "CASE 01: Mashiro's Record," the mystery game follows three members of the Nijisanji Ruins Exploration Club, Mashiro, Kazune Kurusu, and Sister Claire, as they investigate a haunted abandoned apartment complex called Kasumino-so. The story unfolds through a dedicated SNS, videos, audio, and real websites, with the investigation split into two episodes. EPISODE 01 is free for anyone to play. EPISODE 02 reveals deeper truths and requires purchasing the physical item "Mashiro's Ruins Exploration Pouch," priced at 5,000 yen including tax, which contains investigation materials, on-site photos, and a charm. The pouch is available at the Nijisanji Official Store and the Daiyonkyokai Online Shop. Additional merchandise includes exploration sets for each of the three livers, clear files, and an acrylic panel. The project is described as separate from Daiyonkyokai's previous works, depicting new stories that cycle through the seasons.
- Release time: August 21, 2026 at 20:00 JST, with the portal site at parallelcase-2434.net already live.
- EPISODE 02 can be experienced without playing EPISODE 01, though the sources recommend playing EPISODE 01 first because EPISODE 02 connects to its story.
- The pouch contains four cheki instant photos, one document sheet, an omamori charm, and a serial code card, per PANORA's item breakdown.
- Full-body character illustrations are by Mr. Niji Hayashi; background visuals are by Mizushishi.
- The exploration sets, priced 4,400 yen each, include an acrylic stand, an acrylic name badge, a postcard, and sticky notes; each is limited to five per person per transaction.
- The clear files cost 700 yen each and the acrylic panel costs 3,000 yen, also limited to five per transaction.
- Shipping is scheduled for late August 2026 or later; orders ship only when all ordered products are ready.
- ANYCOLOR CEO Riku Tsunomata will publish a two-part advance play report of CASE 01 on ANYCOLOR MAGAZINE, with the first part scheduled for around 17:00 on August 24, 2026; it contains spoilers for goods tied to EPISODE 02.
- Daiyonkyokai started activities in March 2024 and is described by PANORA as a pioneer that developed the ARG market in Japan, known for "Hito no Saifu" and "Kagami no Tokushu Shounen Saisei Shisetsu."
- The project's prologue frames the story across four seasons (spring, summer, autumn, winter), with livers facing unexplained events as a door between reality and the virtual opens.
Synthesized by Yomimono from the 3 cited sources below, including Japanese-language reporting where cited, then editorially reviewed before publishing.