The world will indeed miss the great Hayao Miyazaki. The legendary Japanese filmmaker and manga artist has retired, so his style of mystical, magical movies with deep social themes will need to be carried on by others. Hiroyuki Okiura gives it a go with “A Letter to Momo,” but it almost feels like an audition for the role. Certainly, the film looks and feels the part, but that’s just it: It steps neatly in Miyazaki’s massive footprints and never truly becomes its own creation. Dealing with the death of her father, Momo is visited by a trio of forest goblins, making this too much like Miyazaki’s “My Neighbor Totoro” to avoid the comparison. While “Momo” seems uncomfortable taking its own steps narratively, the film does look great—it’s a sumptuous hand-drawn delight. But there’s just not enough about the story that makes all that visual beauty worth it.