Happiness is one of the basic emotions in children and it occurs in the infant period. We often think that happiness does not require much discussion nor explanation because it is a good and positive feeling. However, happiness in small children can sometimes be incorrectly interpreted, wrongly processed, or negatively manifested in behavior, so this picture book series deals specifically with those situations.

Picture books in the series are focused on the following topics:
- Little fox learned that happiness lives in hearts / Happiness and material things or how to teach children that happiness does not reside outside of us, in toys and things, but that it is in our hearts
- Lioness can be happy for others / Happiness for others or how to teach children that it is important to know how to be happy for others and their success for our own emotional health
- Horse shares his happiness after effort and success / Happiness because of one’s own effort and success or how to teach children do accept help, try hard and then feel happiness and self-confidence because of their own success
- Hamster feels calm and quiet happiness / Active happiness versus calm happiness or how to teach children to calm down, take a break, and feel happy as peace and relaxation within themselves