Manga Translation Specialist Mantra Makes Full-Scale Entry into Game Localization Business

Empowering Multilingual, Fast-Turnaround Global Expansion via AI and Native Translators
— First project, YunYun Denpa Syndrome, localized into 10 languages, achieving a 96.2% positive Steam user review rating —

Mantra Inc. (Headquarters: Bunkyo-ku, Tokyo; CEO: Shonosuke Ishiwatari; hereinafter "Mantra"), a developer of AI technology and provider of translation services specializing in entertainment content such as manga, announces the full-scale launch of its game localization service starting in 2026. Leveraging deep narrative understanding cultivated through manga and novel translation alongside a hybrid workflow combining AI with native translators, Mantra is extending its operations to video games. By delivering consistent quality across multiple languages on short turnarounds, Mantra supports game publishers in expanding globally and maximizing sales opportunities. As its debut project, Mantra handled localization across 10 languages for YunYun Denpa Syndrome (supporting 15 languages in total), published by Alliance Arts Inc.

Handled 10 Languages for YunYun Denpa Syndrome: 1,202 Steam Reviews across Localized Languages Achieve 96.2% Positive Rating; Title Ranks Among Steam's Top Sellers

As the debut project for its game localization service, Mantra localized YunYun Denpa Syndrome (released April 24, 2026). The title is a rhythm adventure game centered around the themes of "Rhythm Game" × "Bizarre Texts," where all playable tracks are "Denpa songs" (quirky, eccentric Japanese pop). Mantra translated the content while bringing out character traits and preserving the unique worldview.

Mantra translated approximately 120,000 Japanese characters into 10 languages—French, Italian, German, Spanish (Spain), Spanish (Latin America), Russian, Portuguese (Brazil), Polish, Turkish, and Thai—in roughly three months. The team also handled multiple text additions and revisions during ongoing development.

As of August 31, 2026, a total of 1,202 Steam user reviews were submitted in the 10 languages localized by Mantra, with 1,156 (96.2%) receiving positive ratings. Notably, 100% of reviews in Polish (62 out of 62) and Thai (20 out of 20) were positive.

Additionally, according to Mantra's internal research, the title ranked in the top 100 of Steam's Regional Top Sellers across six countries/regions: France, Italy, Spain, Russia, Poland, and Thailand.

• Note: Steam user reviews evaluate the overall game experience, not translation quality alone. Review counts and positive rates were compiled and calculated by Mantra based on reviews submitted in the 10 languages handled.
• Note: Steam Regional Top Seller rankings do not reflect language-specific purchase volumes.

Comment from Alliance Arts Inc.

"Meeting user expectations, we took on the challenge of supporting over 10 languages for YunYun Denpa Syndrome. As a multi-language launch of an unprecedented scale for our company, we had initial anxieties, but Mantra's support made it possible. We are truly grateful for their swift response and proactive handling of user feedback gathered from the demo version. We are delighted to see so many warm reviews on the store page following the release."

Bringing Manga Translation Expertise to Game Localization: Mantra’s Game Localization Service

Game localization involves handling a diverse array of text types—narration, dialogue, UI elements, system messages, and item names—while maintaining continuous support for specification changes and text additions during development. As the number of target languages grows, simultaneously balancing quality, turnaround times, costs, and project management becomes a primary challenge.

Mantra has operated at the intersection of entertainment translation services and AI technology R&D, specializing in manga and light novels. Expanding its context-aware expertise and AI-assisted translation and QA workflows to gaming, Mantra provides end-to-end support: from workflow design and multi-language translation to review, glossary/style QA, and handling mid-development updates. Key features include:

• Entertainment Translation Rooted in Narrative Understanding: By analyzing speech styles, character relationships, worldbuilding, and unique humor or pacing, Mantra crafts expressions grounded in context. Moving beyond simple word substitution, Mantra aims for natural, immersive localization. For cross-media IPs, translations incorporate background context from previous and related works.
• Quality Control via AI × Native Translators: AI is utilized for initial drafts, spell/grammar error detection, and glossary consistency checks. Native translators review and refine every line across all languages to ensure contextual accuracy, appropriate tone, and cultural naturalness. Having human experts review all text delivers both speed and high quality.
• Simultaneous, Rapid Multi-Language Deployment: Terminology and progress across all languages are managed centrally for parallel production. Mantra supports expansion into both major global languages and lower-resource languages. Incorporating AI and proprietary QA tools streamlines the workflow, allowing translators to focus deeply on phrasing.
• Support for Mid-Development Changes and Game-Specific Constraints: Text additions and revisions during development are tracked as diffs and applied across all languages. Mantra adjusts phrasing across storylines, UI, and system messages while accounting for character limits and UI display constraints, reducing rework and administrative overhead through release.

Future Outlook

Mantra is currently localizing multiple titles and expanding its language offerings and production network to handle dozens of titles annually from 2027 onward. Mantra provides tailored translation structures suited to project scale and target regions for game developers and publishers.

With this full-scale entry into game localization, Mantra aims to further accelerate the global reach of Japanese IP across media—manga, novels, anime, and games. By advancing AI-human collaborative workflows and developing technology tailored to entertainment-specific expressions, Mantra strives to expand opportunities for creators and global fans to connect beyond language barriers.

Game Title Information: YunYun Denpa Syndrome

• Title: YunYun Denpa Syndrome
• Release Date: April 24, 2026
• Platform: PC (Steam)
• Genre: Rhythm Adventure
• Developers: Alliance Arts, WHO YOU
• Publisher: Alliance Arts
• Supported Languages: 15 languages (10 localized by Mantra)
• Official Website: https://alliance-arts.co.jp/products/yunyun/

About Mantra Inc. Since its founding in 2020, Mantra Inc. has engaged in AI technology research and development specialized for the entertainment sector, providing services such as the manga translation platform Mantra Engine and the English learning app Langaku. Mantra’s achievements have been recognized with awards including the HONGO AI Award (2019), Weekly Toyo Keizai's "Great Startups 100" (2020), AAMT Nagao Award (2021), JEITA Venture Award (Early Edge Award, 2022), Electronic Publishing Award (Challenge Mind Award, 2024), Google Play Best of 2025 (Personal Growth Category Grand Prize, 2025), and Appliv Best App Award (Learning Category Excellence Award, 2025).

Company Overview

• Company Name: Mantra Inc.
• Representative: Shonosuke Ishiwatari, CEO
• Address: 2F Sumitomo Fudosan Iidabashi Bldg., 2-3-21 Koraku, Bunkyo-ku, Tokyo 112-0004, Japan
• Established: January 28, 2020
• Business: R&D of AI technologies specialized for entertainment content, translation services, and language learning applications
• URL: https://mantra.co.jp/

Media / Press Inquiries Mantra Inc.
Game Localization Team: Nakane | PR Representative: Funakoshi
Email: info@mantra.co.jp