Obtained: Talk to Turtle at Kame House when you first arrive at the island as part of the main story
Objective: Find the Book
Talk with Bulma near the entrance to the Kame House to learn that she last saw Turtle heading to the back of the house. Head around back to locate Turtle and speak with him to get a hint that he buried the book in the ground. While facing Turtle, head to the base of the palm tree to the right to locate the disturbed dirt. When you approach the dirt, select “yes” to find the girly book.