Tonkichi Hanamura is one of the three Hanamura triplets, Chinpei and Kanta being the others, collectively known as the Hanamura Triplets. He is the younger brother of Yoshiko Hanamura, a close human friend of Sally.

The triplets are incorrigible and mischievous boys adept at landing themselves in trouble through frequent pranks and unpredictable behavior, which fuels chaotic situations. Their level of mischief matches that of Poron, a young witch girl, and Cub, Sally's shape-shifting assistant.

Later, particularly in the 1989 sequel series, the triplets collaborate with Poron on schemes that escalate into larger problems. A significant instance involves them joining Poron to steal Daimaō's magical horned staff, triggering widespread mischief on Earth. Their antics often intersect with Sally's adventures, sometimes creating complications requiring magical intervention.

The triplets live under the care of their older sister Yoshiko, who acts as their primary caretaker due to their father's demanding work schedule as a taxi driver. This familial dynamic places them within the narrative of Yoshiko's responsibilities and Sally's integration into human life.

Tonkichi functions strictly as part of the collective unit with his brothers. No individual distinctions or unique character development for him separate from Chinpei and Kanta are detailed. The triplets remain a consistent source of lighthearted trouble and comedic relief.