Japan gets a new manga reader app with a language learning twist

Original Japanese text written by. Ryuki Ishii
Translated by. Nick Mosier



Mantra, an AI-based machine translation research and development company, has released a smartphone app to Japan’s App Store called Langaku that aims to teach English through manga. The company also plans to release an Android version. As of now, the app is intended for Japanese users studying English, but Mantra says they’re looking into supporting more languages, including support for studying Japanese.

The app’s key feature is that users can customize the amount of English that appears. Someone may start with only 20% of the text in English and increase the amount as they get more comfortable. Users are free to adjust it to match their personal English level and taste. There’s also a read-aloud feature which could be helpful for learning pronunciation, a dictionary to use while reading, and the ability to check the Japanese text.


Langaku is an app that was made through Mantra’s experience developing a manga translation engine called Mantra Engine combined with their image recognition and language processing knowhow. It was also selected in the publishing company Shueisha’s startup accelerator program Manga Tech 2020 back in September of 2020.

When learning a language, finding something to read that matches your skill level and interest is difficult. According to a survey by Mantra of 4,300 people who tried out extensive reading to study a second language, 25% say they stopped because they couldn’t find books or content they were interested in.

The Langaku app went into beta testing in June of 2021 to solve this problem. By combining Shueisha’s beloved manga catalog (and usage of their official English translations) with AI powered language support technology, they claim to have made an experience where language learners can have fun continuing to read.


As of now, the manga on offer is centered around Shonen Jump favorites, with over 30 different series available including Chainsaw Man, Demon Slayer, Jujutsu Kaisen, One Piece, My Hero Academia, Spy x Family, Kaguya-sama: Love Is War, and Death Note, with more scheduled to be added monthly.

From a language learner’s perspective, Mantra especially recommends shoujo manga. This genre of manga tends to feature high school or university students with stories that revolve around their daily lives, so readers will get to see plenty of simple and practical expressions to use. For the app’s beta test, there was a feature where users could ask about English phrases they didn’t understand, but this feature is not included in the commercial release due to resource issues (Shueisha Online).


Langaku is generally free to download and use with users either unlocking manga chapters with the one daily ticket they receive or with the in-app currency that’s available for purchase. Unlocked chapters are available for 48 hours. There’s also the monthly Langaku + plan available for 980 yen (roughly $7.25). This plan provides subscribers with two daily tickets and 980-yen worth of the in-app currency each month. The plan also removes the 48-hour restriction so subscribers can read without worrying about time limits.

Being able to customize the proportion between how much of two different languages appear while reading is an interesting idea. It could also be helpful for those interested in translation to be able to swap between both languages and compare the lines.

The app is currently aimed at Japanese users studying English, but Mantra does say they’re looking into using it for Japanese study as well. If that becomes a reality, perhaps we’ll see the Langaku app release on the App Store internationally as well.

.Ryuki Ishii
.Ryuki Ishii

Former JP AUTOMATON editor & former AUTOMATON WEST editor in chief (*until May 2023)

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