A hundred foreheads lower themselves to their hearts in winter in grief. There were once many of their kind, the forehead peoples, but now there are only a hundred left after this harsh winter took the rest of them. Their grief is immense.
Their grief intensifies because all of the foreheads they lost belonged to youths (ゆう). Dead youths everywhere. Now there's no one left to repopulate the world.
Currently there are no similar looking kanji which exist in the WaniKani learning system