Langaku, the Manga-Based Extensive Reading App, Officially Announces Launch for Educational Institutions

— Results from Tokyo high school pilot program revealed: over 90% of students reported increased exposure to English —

Mantra Inc. (Headquarters: Bunkyo-ku, Tokyo; CEO: Shonosuke Ishiwatari), operator of the manga-based extensive English reading app "Langaku," is pleased to announce the official launch of its service for educational institutions. Simultaneously, a dedicated inquiry desk for educational organizations and professionals has been established.

Langaku is an app designed to help users naturally develop an "English brain" through the enjoyable practice of extensive reading via manga. Based on the principle that "learning lasts when it’s fun," the app helps students habituate English study and naturally improves reading comprehension and vocabulary.

Extensive reading—a proven method for acclimating the brain to a foreign language—was famously championed by the legendary novelist and former English teacher, Natsume Soseki:

"Young people studying English should, once they reach a certain level, read English books profusely and recklessly without looking up every word in a dictionary. Even if there are parts they don't understand, they should skip them and keep pushing forward; eventually, they will understand. (...) In short, those learning English should do so through natural habit, much like how Japanese people learn their own national language." (p.23) — Koki Kawashima (2000), "Natsume Soseki: The English Teacher," Shinchō Sensho

Through familiar and engaging manga content, Langaku provides a "sustainable English environment" for both school and home. Along with this announcement, Mantra is releasing the results of a pilot implementation conducted at a metropolitan high school in Tokyo.
■ Pilot Results at Tokyo Metropolitan High School: Confirming the Effects of Extensive Reading

In this initiative, all second-year students at a Tokyo metropolitan high school utilized Langaku for extensive reading practice. Over a period of 150 days, students performed an average of 32,000 words (max: 332,000 words) and 9.4 hours (max: 114 hours) of self-study. Note: For reference, a standard 6-year middle/high school textbook contains approx. 30,000–50,000 words; a single novel is approx. 70,000 words.

The survey (272 respondents) confirmed that the app successfully addressed challenges such as "difficulty in maintaining study habits" and "lack of home study," creating a natural habit of engaging with English in daily life.

■ Key Survey Results

Following the introduction of Langaku, significant changes were observed in how students interact with English, particularly during "commutes" and "free time."

  • Increased Exposure to English
    • 90.1% of students who used the app 3+ times a week reported an increase in English exposure.
    • 72.8% of all users felt their time spent with English had increased.
  • Changes in Motivation and Habits
    • 75.3% of students expressed a desire to study English more.
    • The percentage of students wanting to study English rose from 48.1% (pre-utilization) to 75.7% (current) (+27.6pt).
  • Overcoming Negative Perceptions
    • 54.5% of students who previously disliked English reported an improvement in their attitude.
    • The number of students who felt they were "very poor" at English dropped from 28 to 9.
  • Improved Reading Skills and Behavior
    • 54.9% felt their reading speed had increased.
    • 36.6% began looking up words voluntarily.
    • 18.5% of frequent users (3+ times/week) reported that their "test scores improved."

■ Voices from Students

"Because it’s manga, it doesn't feel like 'studying,' making it easier to pick up." "I can study while reading manga during my commute or in my spare time." "Even though I’m bad at English, I’m able to use this proactively."
"I want to know what happens next in the story, so it’s easy to keep the habit going."
"The appeal of enjoying manga in English is truly unique."

■ Why "Extensive Reading" in Schools Now?

According to surveys by the Ministry of Education, Culture, Sports, Science and Technology (MEXT), securing opportunities for English exposure outside of class remains a major challenge¹. Additionally, many students develop a complex regarding the language, as learning often centers strictly on test preparation².

Against this backdrop, there is an increasing need for learning environments that allow students to engage with English daily and sustainably without undue stress.

■ Inquiry Desk for Educational Institutions

Effective today, we have opened a dedicated inquiry desk for schools and educators. For consultations regarding school-wide implementation or trials, please contact us via the form below.
▼ Inquiry Form for Educational Institutions:
https://docs.google.com/forms/d/1U9Ek4xDcfYeX0HZjpUzJMMZinLFNzebmutIqjLluPEc/viewform?edit_requested=true

■ About Langaku

Langaku is an app that provides an immersive learning experience through popular manga. With over 90 titles including ONE PIECE and Demon Slayer: Kimetsu no Yaiba, users can acquire English skills naturally while enjoying world-class stories.

Unique Learning Support Features:

  • Switch Languages: Toggle between English and Japanese with a single tap on any panel.
  • AI Explanations: AI provides context-specific explanations for idioms and slang.
  • Adjustable Ratios: Change the ratio of English to Japanese panels based on your proficiency level.
  • Audio Features: Includes narration and an auto-play mode.

■ About Mantra Inc.

Founded in 2020 with the slogan "Bringing manga to the world in every language," Mantra Inc. develops specialized AI technology for manga. The company provides "Mantra Engine," a high-speed translation tool, and "Langaku," the English learning app.

Awards include: HONGO AI Award (2019), Toyo Keizai "Amazing Venture 100" (2020), AAMT Nagao Award (2021), Google Play Best of 2025 (Self-Improvement Category) Grand Prize, and more.

  • Company Name: Mantra Inc.
  • CEO: Shonosuke Ishiwatari
  • Location: 2F Sumitomo Fudosan Iidabashi Bldg, 2-3-21 Koraku, Bunkyo-ku, Tokyo
  • Established: January 28, 2020
  • URL: https://mantra.co.jp

Contact: Mantra Inc. (Attn: Norimine / Funakoshi) Email: info@mantra.co.jp

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