Although summer comes every year, if we look at it with fresh eyes, it shows us a completely different view. This book presents three types of lines that represent summer. Summer is a world made with ten straight lines. Summer is a sea where dancing lines weave hearts together. Summer is an island you cross by following the wavering lines. Let’s walk along the lines of summer. Music flows, and stories are heard. These three lines represent oriental melons, melons, and watermelons.