This book introduces his friends from the perspective of Ensk, a fourth-grade pupil, through his diary of a school year. The other part of the book is a letter from his family to Ensk. The contents of the letters are very rich, but each letter reveals the sincere love between family members and makes them feel at home. In addition, the "monthly story" arranged by the teacher allows you to learn to love your motherland with the protagonist. This book is full of deep warmth.