Japanese learners frequently confuse the terms 原因 (gen’in) and 理由 (riyū), both of which are commonly translated as “reason” in English but hold distinct nuances in Japanese communication. This video by Kaname Naito addresses this common confusion, providing clear explanations and practical usage tips to help learners choose the correct word depending on the situation.

Kaname Naito systematically breaks down the core meanings of each term. 原因 (gen’in) typically refers to the objective cause or the root source of an event, such as the cause of an accident or the cause of an illness. It deals with factual or scientific causality. In contrast, 理由 (riyū) is used when expressing a subjective reason or motivation for an action or opinion—such as the reason for being late, or explaining why one chooses a certain option. Naito uses various example sentences to show the difference, highlighting how native speakers would select one term over the other based on context.

For learners aiming for fluency and natural communication in Japanese, understanding the specific use cases of 原因 and 理由 is essential. The video provides a practical guide for mastering this subtle yet important distinction, reducing the risk of miscommunication. Kaname Naito also mentions resources such as his beginner course and suggests ways to deepen your Japanese learning journey.