Japan typically digs in its heels against outside customs. To win acceptance here, such customs must first measure up to Japan's high standards of cultural attainment.
Which means . . . they gotta make money.
Thus, through the years Japan has been trampled over by Western cash cows like Halloween, Christmas and Valentine's Day. Such foreign customs, or rather the Japanese versions of such, have brought smiles to countless young children and romantic couples and, at the same time, have given Japanese merchandisers reason to live. And live well.