Hibiki

Overview

Hibiki (響き) is a full-featured Japanese language learning platform we built from the ground up. It combines a clinically-validated Spaced Repetition System (FSRS algorithm) with AI-powered translations, interactive verb conjugation drills, and a personal notes workspace — all in a single fast app.

The Challenge

Existing Japanese learning tools are either too rigid (Anki) or too gamified and shallow (Duolingo). The goal was to build something that actually works for serious learners: adaptive, AI-assisted, and comprehensive — without being overwhelming.

Our Approach

We architected a full-stack React + Vite app backed by Supabase for user data and a Vercel serverless API layer. The FSRS algorithm drives vocabulary scheduling. Claude AI handles real-time translations and grammar explanations. A sentence reorder game teaches SOV word order through play. PDF parsing lets users import vocab from study materials.

What We Built

• FSRS spaced repetition — the same algorithm used by top memory researchers
• Claude AI translations with grammar breakdowns in context
• Sentence reorder drag-and-drop game for SOV word order
• Verb conjugation drill engine with 12 tense/form combinations
• Personal Notion-style notes with favorites and tagging
• Kana reference charts (Hiragana + Katakana)
• PDF import for custom vocabulary sets
• JLPT-level filtering across all grammar patterns