資格のキーホルダー · From Otsu-4 to all six Otsu classes
Hazardous Materials, Otsu (incl. Otsu-4)
Practice only what your selected class requires.
Covers Otsu classes 1–6, combining shared knowledge with class-specific questions for standard and exempted exam formats.
Classes 1–6280 questions per selected classStandard and exempted mocks
680 questions total

Before you start
- iOS app
- 資格のキーホルダー 宅建・簿記・FP・ITパスポート
- What it does
- One app with practice questions for 49 Japanese exams across 34 qualifications, each with its own study record and exam date.
- Content and features
- 49 exams, 34 qualifications / Explanations for every choice / Automatic review of missed questions / Daily target from your exam date
- Requirements
- iOS 16.0 or later
- Free access and purchases
- The first 10 questions of every qualification are free. Full questions and mock exams are a one-time in-app purchase per qualification, not a subscription.
- Before choosing
- Japanese-language exam practice. Not an official app of any exam body and no pass guarantee. Most questions download when you open a qualification; the first 10 work offline.
iOS facts checked: · Current App Store listing and purchase terms ↗
3-MINUTE CHECK
Try three questions.
Can you recall the reason?
The mini diagnostic is in Japanese, with a short explanation after each answer. No sign-up is required.
QUESTION 1 / 3
第4類(引火性液体)の性質として、消防庁の概要と一致するものはどれか。

CONTINUE IN THE APP
Continue in the Keyholder app.
Move from focused repetition to exam-format mock tests while keeping your study history.
This page and app are independent study aids, not official exam-authority products. Check current official information before taking an exam.