Takeshi Okamoto, known as Casey in the 4Kids English adaptation, is a young boy living in the Third Street neighborhood and attending Third Street School. He cares for Tama, an adventurous cat originally gifted by his grandmother. Casey's daily life involves riding his bicycle and stargazing, reflecting his calm and observant nature. He shares a friendship with Emi Hanasaki (Amy in the 4Kids dub), owner of Momo, a cat often involved in Tama's escapades. While generally unaware of the full scope of the animals' secret lives and conversations, he possesses a general awareness of their activities and relationships.

His narrative role differs between versions. In the original Japanese *Tama of Third Street: Have You Seen My Tama?*, he typically provides concluding episode narration, summarizing events with limited insight into the animals' perspectives. The 4Kids adaptation expands this role, giving him more extensive narration throughout episodes.

Across franchise iterations, including the 1993-1994 television series and subsequent media, Casey's core characteristics remain consistent. He is portrayed as a responsible, dedicated pet owner deeply concerned with Tama's well-being, frequently searching for the cat when it goes missing – a trait aligning with the series' inspiration from a real-life missing cat poster. His family includes his mother, Kimie Okamoto. Later adaptations, such as the 2016 web shorts and the 2020 series *Uchitama?! ~Uchi no Tama Shirimasen ka?~*, continue featuring him as Tama's owner.