Primarily known as Dekoppachi in most sources, this character also appears under the name Dekkoha. Dekoppachi is a 10-year-old boy and the best friend of protagonist Atarō. His notoriously short temper pairs with a strong sense of justice, frequently driving him into confrontations to protect Atarō or their shared interests. He possesses an exceptionally durable head, a trait he effectively utilizes in fights.

Dekoppachi originated from the character prototype Dabo, created by Fujio Akatsuka in the 1962 one-shot manga "Chankichi-kun". Within the "Mōretsu Atarō" narrative, he remained unnamed until the 13th chapter of the 1968 serialization, when a reader contest selected "Dekoppachi". His personality includes being popular with girls, and he finds motivation in their attention or feelings.

During the original manga's run, Dekoppachi gained expanded focus in the spinoff series "The Flower of Dekoppachi", published in both the weekly and deluxe editions of Shōnen Sunday from 1968 to 1970. These stories placed him in alternate universe settings and sometimes featured other characters from Akatsuka's works. Selected narratives from this spinoff were adapted into anime episodes.

Following the main "Atarō" series, Dekoppachi appeared in the short-lived spinoff "Fujio Akatsuka's Gag + Gag", serialized in Weekly Shōnen Sunday from July to September 1970.

In the 1990 anime adaptation, the character is credited as Dekkoha, voiced by Kyōko Tongū. His narrative role and core characteristics remain consistent with the Dekoppachi established in the original manga and prior adaptations.