Shima almost 11 years ago “残暑お見舞い申し上げます” (literally, "stating a late summer inquiry") is a message written on cards sent in the late summer to friends, asking about their health and status. No easy translation, as we don't do this at all.
WatcherCCG over 10 years ago AnimeMaster said:Cirno looks so happy to see him it makes me happy insideThat note's got to be from Letty. She must be on the outside somewhere that has winter.