Sheeee-it! Can’t the JR –Japan Railway Corporation— get simple English right?
What they want to say here is “Happy Manners”…that is, “manners” refer to politeness which is the meaning they want. The word “manner” is a neutral state that has nothing specifically to do with being polite or impolite.
What makes this worse is the the JR screwed up the Scholastic Inc. educational character Clifford, the big red dog, Sheesh.