Rule
If you play music with your fins, one rule is that you must be a fish. You can’t play music using fish fins that don’t belong to you. That’s the rule. And it’s also rude.
Imagine a fish playing music using his fins. What kind of a song is it? Imagine it in your head as you see a sign with the fish fin rule on it.
てん
None
None
There’s also a rule in place to limit the amount of fish fin musicians. No more than ten (てん) are allowed to gather and play their music together. That’s the rule. No more than ten.
Picture a group of ten (as per the rule) fish playing music with their fins. Now the song can be louder and more intricate. Imagine it playing in your head.