Ask HN: Simplest Explanation of YouTube Content ID for a Child? (in Japanese)

Exactly what it says in the title. Some background: A young student of mine who only speaks Japanese received a YouTube Content ID claim email for a video they uploaded, but it was in English. My student only speaks Japanese so they asked me for help (big scary email in English = quite the shock I imagine). The flagged video is just of them sketching with faint background music playing through a playlist (probably on their portable music player). Most of the videos are like this with most at a very very low view count. So I assume this was automated which would make sense because I checked the claimed song and I don't even think it was played. Similar type of music but I'm 99% certain that it's a false positive. So I'm not exactly sure what advice to give. To be safe, I'll double check with my student to make sure it's not me mishearing the Japanese lyrics before giving any advice. I can explain the email in Japanese, but it'll be a bit difficult to explain why it happened and what Content ID exactly is. My student probably has never even considered that something like this is possible or a problem. So, I'm hoping someone can point me to: 1. A simple, for kids, explanation of Content ID and what it means to them and their hobbyist videos. 2. Hopefully a translation of the Content ID claim email so I don't have to translate it myself. I've only been able to find a Content ID page in Japanese and if it's anything like the English one, I seriously doubt a child would understand it.