Children's literature tends to revolve around several of the same themes and morals, like acceptance, love, or friendship, but 'Not Just a Cup' takes on an atypical subject for the genre: design. The book, which has written and illustrated by acclaimed Japanese design firm Nendo, features a shapeshifting coffee cup and its journey to the perfect design.
The plot of Not Just a Cup opens with the titular cup realizing that it doesn't have a spoon for stirring itself. This leads it on a series of transformations, with the cup taking on different shapes as it ponders the different ways that it could be used. The message of the story is that nothing people use in their daily lives is boring as long as its given enough care and consideration.