Many of you have probably heard of 暗黙の了解 (あんもくのりょうかい – “anmoku no ryoukai”), the unspoken/implicit agreements that allow fan-artists in the manga industry to create doujinshi and other fan works. This term applies to a lot of social interactions as well – for example, when you can’t (or don’t want to!) go to a party, you respond “ちょっと・・・” to the invitation, and it is implicitly understood that you’re declining, even though you never directly said “no”.
Along the same vein, 暗黙のルール are certain social “rules” that everyone somehow knows about, but no one actually ever teaches. These kind of “implicit rules” can be things that are considered so obvious there is no need to speak about them (like the fact that you’re not supposed to blow your nose in public, or eat while walking on the sidewalk).
So with Valentine’s Day/White Day, the “rules” are considered obvious, so no explanation is added along any of the candies/gifts on display at the shops.
Every culture and society has these kinds of rules, and they differ from country to country, but Japan does seem to have a lot of them! Can you think of any other interesting 暗黙のルール? Let us know via Twitter or Facebook!