Otsu-4 Anki Club: Kiken-butsu
Japan hazmat Class 4 exam prep
Only for iPhone
Free · In‑App Purchases · Designed for iPhone. Not verified for macOS.
iPhone
The Otsu-4 (乙4) hazardous-materials handler exam trainer for Japan — the license that raises hourly wages at gas stations and warehouses across Japan.
• 911 original drill questions with explanations (regulations / physics & chemistry / properties & firefighting) — real count, no inflated numbers
• 26 original Japanese mnemonics (goro) for designated quantities and key facts
• Full-format mock exam: 35 questions, 2-hour timer, graded with the real rule — 60% or better in every subject
• Leitner spaced repetition brings back exactly what you were about to forget
• Reference table of 30 Class-4 substances: quantities, flash points, solubility, extinguishing agents
• Study features work fully offline, including in airplane mode — no account or internet needed to learn
A banner appears at the bottom of the screen, and a full-screen ad may appear at natural breaks. An optional one-time "Remove Ads" purchase hides both.
Note: exam content is in Japanese (the exam itself is administered in Japanese). Original study material, not a copy of any commercial past-question book. Interface available in English, Japanese and Simplified Chinese.
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Fixed internal ad configuration and improved overall stability.
The developer, 丽佳 施, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
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Information
- Seller
- 丽佳 施
- Size
- 7.5 MB
- Category
- Lifestyle
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - Mac
Requires macOS 14.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
English and 2 more
- English, Japanese, Simplified Chinese
- Age Rating
4+
- 4+
- Contains
Advertising
- In-App Purchases
Yes
- Remove Ads $0.99
- Copyright
- © 2026 LIJIA SHI