The naughty blue cat is a series of stories whose main protagonist is the Blue cat (the hero for the Greek letter "Γ" gamma). The vocabulary is simple and the book is aimed at children for whom Greek is a second or foreign language. These short stories can also be read to younger, pre-school aged children. The stories have simple plots in an imaginary world, Letterland (Grammatochora), where people, animals and fairies co-exist. In general these stories are a good auxiliary tool for teachers and students learning Greek as a foreign language, irrespective of what learning method they use.