I got a message from @kirschner, and wrote: https://lists.gnupg.org/pipermail/gnupg-users/2015-February/052495.html

In Japan, today is the day to exchange chocolates. No, it's not public key exchange, nor disk exchange.

My children keep trying to intercept chocolate from my wife to me, so, I haven't got it yet. Instead, I ate daifukumochi (Japanese traditional sweet) from my niece.

This year is peaceful, as 14 February is weekend. Most schools ban the exchange of chocolates and have many troubles. I know that nephew got punished in school because of receiving a chocolate or two, in the past.