Following how it's done America, it is celebrated on the second Sunday of May, and it's customary to give carnations as a gift!
Pretty sure the kanji for 習って is wrong? As it is, it would meaning "learn" (kind of like "learning from America"), but it would make more sense as 倣って, "emulate" (kind of like "following the example of America"). Both are read as "naratte", so it seems plausible.I wasn't able to get you any more than this one, but...
