Meeting someone is about understanding, and understanding is about knowing the heart. Leaving his hometown, Diudiu arrives at the Monster Apartment on Monster Planet with hopeful dreams for the future. There, he meets a group of quirky friends with vastly different personalities, and thus begins his brand-new life. When Kaka, who has a cleanliness obsession, occasionally goes on business trips, the apartment falls into chaos, making everyone realize the importance of cleanliness. After things mysteriously disappear, Diudiu suspects an unknown creature is lurking in the apartment, only to later discover it’s the reclusive scientist, Dr. Qi. A meteor shower helps the constantly bickering brothers, Kaka and Chacha, realize that brotherhood is more important than anything. Living in this warm and welcoming Monster Apartment, Diudiu learns many valuable lessons, and he will continue to embrace this life here.