When Bi Bi goes to sleep, her grandfather often provides her with a "pillow hand." She prefers this cozy alternative to a regular cotton pillow because it offers warmth and comfort. Today is no exception. As soon as Bi Bi lies down, she rests her head on her grandfather's "pillow hand" and falls into a deep slumber.

Around midnight, her grandfather's right arm protests, saying, "I'm tired!" The left arm chimes in, "I'm feeling great, I have plenty of energy; let me take over!" In response, Bi Bi shifts and repositions her head on her grandfather's left arm.

As the night deepens and the temperature drops, her grandfather's "pillow hand" is covered with a blanket, keeping Bi Bi warm. Suddenly, she startles upon hearing a voice saying, "Oh, I'm so cold!" Bi Bi turns her head to investigate and, in the dim light, she sees her grandfather's right arm sticking out from under the blanket. It turns out that while he was occupied with his left arm, his right arm was left exposed, becoming cold and prompting its complaint. Oblivious to it all, her grandfather continues to sleep.

Feeling sympathetic for his right arm, Bi Bi slowly moves to the right side, resting her head on his right arm. The little girl also takes care to tuck the blanket securely around her grandfather's left arm. "Oh, it's so cozy, so warm..." Bi Bi feels content and drifts into a deep sleep, embraced warmly by her grandfather's arm.