"Kero Kero Keroppi no Bikkuri! Obakeyashiki" is a short anime series centered around Keroppi, a cheerful and adventurous frog, and his friends as they explore a mysterious haunted house. The narrative begins when Keroppi, along with his close companions Keroleen and Koroppi, stumbles upon an eerie, abandoned mansion while playing in the forest. Intrigued by the rumors of ghosts and supernatural occurrences, the group decides to investigate, driven by curiosity and a sense of adventure.

As they venture inside, the friends encounter a series of strange and spooky phenomena, including moving objects, eerie sounds, and shadowy figures. Each room of the mansion presents a new challenge or puzzle, testing their courage and teamwork. Despite their initial fears, Keroppi’s optimistic and determined nature keeps the group moving forward. Along the way, they meet other characters, such as the mischievous but harmless ghost Denki, who adds both humor and tension to their exploration.

The story unfolds through a series of episodic encounters within the mansion, with each episode focusing on a specific room or challenge. The interactions between Keroppi and his friends highlight themes of friendship, bravery, and problem-solving. While the haunted house initially seems terrifying, the group gradually uncovers the truth behind its mysteries, revealing that the supernatural elements are often the result of misunderstandings or playful tricks rather than genuine danger.

The series maintains a lighthearted tone, blending mild suspense with humor and charm, making it accessible to younger audiences. Keroppi’s unwavering positivity and the camaraderie among the characters serve as the emotional core of the story, ensuring that the spooky elements never overshadow the sense of fun and adventure. By the end of their journey, Keroppi and his friends not only solve the mysteries of the haunted house but also strengthen their bonds, leaving them with memorable experiences and a newfound appreciation for teamwork.