[CEOs of Companies Selected for the 2025 Daejeon CCEI Pre-Startup Package] Language Forest, A Startup Developing Personalized AI Language Learning Systems

Chanjoong Lee CEO of Language Forest

-Generates learning content tailored to the learner's emotions, sentiments, and proficiency level based on user data

-Automatically records learning history and visualizes the learner's progress and emotional data

Language Forest is an AI-based EdTech startup that provides personalized language learning by turning a user's daily experiences into educational content. Founded in July 2025, the company launched its AI language learning app English Forest, focusing on creating an environment where learners can use a language consistently and without pressure. CEO Chanjoong Lee (28), who leads the company, identified the limitations of traditional language learning based on his diverse experience across the educational content and gaming industries.

“Education and gaming essentially share the same principles”, said Lee. “Once you understand the rules, it becomes fun; and once it's fun, immersion follows naturally. I believed language learning could be designed in the same way. I felt a strong conviction to realize this quickly by utilizing AI technology in line with current trends.”

To formalize this vision, Lee conducted interdisciplinary research merging cognitive psychology, learning science, and information systems at the Data Strategy Lab within the KAIST Graduate School of Future Strategy. His goal is to move beyond learning by solving more problems toward creating a sustainable learning experience.

The core service, English Forest, is a personalized AI system that uses the user's daily stories as learning material. It differentiates itself from existing services from the very start, rather than unilaterally providing a fixed curriculum, it offers customized learning tailored to the user's individual data.

Context-Driven Content, Learning problems for the day are generated based on the user's daily life and emotional data. By expressing their own day in English, learners become naturally immersed, leading to higher retention.

Cognitive Shift over Translation, The service focuses on thought transformation rather than simple translation. When a user tries to express a Korean sentence in English, the AI provides feedback in real-time. This process ensures that English is not just a language to be memorized but a language to be used through thinking.

Visualization of Growth, Learning records are automatically accumulated and visualized. Users can track not only their study volume but also changes in their emotional state and growth trends, allowing them to perceive their own progress and stay motivated.

Currently, Language Forest is focusing on refining its service for domestic users, specifically targeting women aged 25 to 35 to experiment with structures that encourage consistent learning without pressure. Starting with a Japanese language service this year, the company plans to expand into the global market in the long term.

Regarding future plans, Lee stated, “Language Forest will create a world where anyone with the will can learn easily. We are starting with English, but our ultimate goal is to create an environment where opportunities are never blocked due to language barriers.”

Established: July 2025
Core Business: Development of mobile AI and IT systems for language learning.
Key Achievements: Top 5 in the KAIST E5 Startup Competition (Nov 2024), Excellence Award at the Sogang University Startup Competition (Dec 2024), Research collaboration with KAIST Data Strategy Lab (Mar 2025),Selected for the 2nd Preliminary Startup Package (May 2025), Selected for the KIPO IP Stepping Stone Support Project (Aug 2025), Launched on iOS and reached Top 11 in the Free Education App Charts (Oct 2025), Grand Prize at the Sogang University Tech Startup Competition (Dec 2025)

reporter jinho lee
jinho2323@hankyung.com