"Kero Kero Keroppi no Daibōken: Fushigi na Mame no Ki" is a children's anime series centered around the adventures of Keroppi, a cheerful and curious frog, and his friends. The story begins when Keroppi and his companions discover a mysterious bean tree in their peaceful village. This tree, known as the "Fushigi na Mame no Ki" (Mysterious Bean Tree), possesses magical properties that transport the characters to various fantastical worlds. Each episode typically involves Keroppi and his friends embarking on a new adventure after climbing the tree, encountering unique challenges and meeting diverse characters in these alternate realms.

The main characters include Keroppi, the optimistic and brave protagonist; his best friends, the shy and kind Keroleen and the mischievous yet loyal Koroppi; and their other companions, such as the wise and gentle Ganta and the playful twins, Picky and Poky. Together, they navigate the whimsical and often unpredictable environments created by the bean tree, solving problems, helping others, and learning valuable lessons about friendship, teamwork, and perseverance.

The narrative structure is episodic, with each adventure standing on its own while maintaining a consistent theme of exploration and discovery. The magical bean tree serves as a gateway to imaginative settings, ranging from enchanted forests and underwater kingdoms to futuristic cities and dreamlike landscapes. These settings often reflect the characters' growth and the moral lessons embedded in their experiences. The series emphasizes lighthearted humor, positive values, and the joy of adventure, making it accessible and engaging for its target audience of young viewers.