It is enough to have a confidant in life, and the world should treat it with the same heart. In this life, the greatest luck is to meet at least one trusted confidant. With their friendly hands, there is tolerance in times of lows or hardships, misunderstandings, eternal trust, reminders in times of complacency, and sharing in times of happiness and success. This is the happiness of life.
Recommendations on the general books on making friends:
Recommendations on the books for parents to help their children make friends: The Science of Making Friends
Recommendations on the books for children on how to make friends: Leonardo the Terrible Monster