Kaika Lab

About Kaika Lab

About us

Kaika Lab is an independent software studio in Osaka, Japan. Michael Jiang founded it in July 2026. We make exam-prep apps and study materials for people learning Korean and Japanese, and tools for the teachers who teach them.

Our products

Available now

  • TOPIK PILOT

    Korean, TOPIK prep

    A Korean study site and an Android app for the TOPIK exam. The app is sold as a subscription on Google Play.

    Study site (Japanese)Word lists (English)Google Play

  • JLPT-GO

    Japanese, JLPT prep

    Practice tests for JLPT N1 to N3, with an explanation for every question.

    Google PlayStudy pages

  • Cloze Maker for Japanese and Korean

    For teachers, Google Docs™ add-on

    Turns a passage into a cloze worksheet and an answer key. Listed on the Google Workspace Marketplace since September 2026, after Google's OAuth verification.

    Workspace MarketplaceProduct page

  • OPENVOIX

    Multilingual learning app

    An Android app for learning English, Japanese and Chinese by listening and typing.

    Google Play

  • Learn Korean with a Drama

    Educational media

    A 100-episode short drama in everyday Korean. A new episode goes out on YouTube every day.

    Episodes (Japanese)YouTube

How the business works

Business model

Our main source of revenue is subscriptions to our exam-prep apps. TOPIK and JLPT scores are used in university admission and hiring, so learners have a clear reason to pay for practice tests and explanations before exam day.

The free study site, word lists and drama episodes are where learners first find us. From there we point them to the apps, where they can practise in exam format.

Cloze Maker is free for now. We are measuring installs and repeat use before deciding on paid features. JLPT-GO also starts with free practice tests, and a paid plan will follow.

Kaika Lab is run by its founder, and our servers run on cloud services that charge by usage. This keeps our fixed costs low.

AI in our products

Claude API

We plan to use the Claude API inside our products: for an AI tutor that explains grammar and answers learners' questions in English, Japanese and Korean, and for a pipeline that drafts and checks practice questions and explanations before they go to human review.

Company

Details
Name
Kaika Lab
Founder
Michael Jiang
Founded
July 2026
Structure
Founder-led independent studio
Address
Osaka Ekimae No.3 Bldg. 29F, Room 1-1-1, 1-1-3 Umeda, Kita-ku, Osaka 530-0001, Japan
Email
support@kaikalab.com
Google Play
All Kaika Lab apps