Tightly wrap the cream cheese in a 12-by-8-inch piece of cheesecloth.
Lay a 12-inch piece of plastic wrap on a work surface. Using slightly wet hands, spread 1/4 cup of the miso into a rectangle that's roughly the size of the cream cheese. Set the cheesecloth-wrapped cream cheese on top of the miso; spread the remaining 3/4 cup of miso all over the top and sides. Wrap in the plastic wrap and refrigerate for 4 days.
Unwrap the cream cheese; discard the plastic wrap and cheesecloth. The spread can be served sliced or whipped, with crudités, rice crackers and shichimi togarashi.