Gyakukou no Kuru-chan

Kuru-chan lives happy days every day. She enjoys delicious meals, a comfortable home, and is loved dearly by her honest and kind mother. However, her mother is still not happy enough. That is why Kuru believes she must make her mother happier and happier. Because her mother's happiness is her own happiness. She believes she was born for that purpose.

(Source: Kodansha, translated)