White Day - 14 March, exactly one month after 14 February. On Valentine's Day women in Japan hand out chocolate to the men (I explained it before here). Exactly one month later, it's up to the men to return the favour. Usually they give out cookies, marshmallows or chocolate. Just like the women a month earlier, men are expected to give presents to colleagues, as well as their girlfriends. They should also man up and return at least as much as, but preferably 3 times the worth of the Valentines present!
Honestly, these cookies are reason enough to bake them. It's an easy recipe and the cookies are simply delicious (simply - easy, get it?). I bet you have all the ingredients you need in your house right now!