- —Ataru Hori
|Date of Birth||July 7, 1984|
|First Appearence||Mr. Driller G|
Ataru is japanese with gray hair that covers his right eye. He has brown eyes and he's never seen wearing anything else than his driller outfit. He wears a black helmet with spike-shaped earpieces. His suit is a dark blue color with light blue sleeves and a white cross on his chest, he also wears a red scarf. He is sometimes seen with a twig on his mouth.
Ataru is Susumu Hori's older brother, and is Taizo Hori and Toby Masuyo's older son who ran away from home. He is a rogue driller who lacks an official driller's license, and lives in an area unknown to any of the main characters in the series, thanks to a confrontation with his father, whom Ataru also holds a grudge against. He is a loner-type who usually attempts to look 'cool', and has a companion named Usagi. He considers his younger brother, Susumu, to be a "sweet kid".
- Ataru's max top speed surpasses all of the other drillers, including Anna Hottenmeyers'. However, he has a higher air consumption rate.
- Ataru is the only asymmetrical Mr. Driller character to date, as a result, he's given two different sets of sprites, one for facing left and other for facing right.
- Ataru's scarf originally belongs to an old friend of his called George. Both of them traded scarves and now George wears Ataru's original yellow scarf.
- Ataru suffers from a severe case of Chiraptophobia (fear of bats).
- In Susumu's Japanese profile, it states that he was the only member in the family that didn't know about Ataru, meaning that Ataru must have ran away from home at a very early age and Susumu eventually forgot about him.