Be, also known by the alternative name Nero, is a male cat and one of the main animal friends living on Third Street. His birthday is on April 6th. Be is the pet of the Kawahara family, who run the local newspaper delivery shop in the neighborhood. This association gives him a deep familiarity with the local area; he is recognized as the cat who knows the geography of Third Street better than anyone else, often discovering hidden paths and keeping track of where his friends are.

In terms of appearance, Be is a black cat with a white patch on his face and a white tail. His most distinctive feature is a bandage, or adhesive plaster, that is always stuck on his head. Among his feline friends, he is also noted for having three whiskers, which is unique to him.

Personality-wise, Be is driven by a strong sense of curiosity. Despite his role as the cat from the newspaper shop, he ironically has a difficult time waking up early in the morning. To compensate, he greatly enjoys riding in the baskets of the delivery bicycle, which is one of his favorite activities. He is frequently seen in the company of his two close friends, the adventurous Tama and the boisterous Tora, often getting into trouble or exploring alongside them. His role in the group is that of a local expert, using his knowledge of the neighborhood's secrets and shortcuts during their many adventures. While he shares a similar black-and-white coat pattern with the stray cat Nora, they are distinct characters; Be is active and owned by a family, whereas Nora is more solitary and independent. No information is available about significant character development or changes he undergoes throughout the series.