Noby Nobi is the other main character of most stories. He is a fourth grader in Tokyo's Nerima Ward and an only child. He wears glasses, a red or yellow polo shirt with a white collar, and blue or black shorts. Noby is dumb, uncoordinated, dim-witted, weak, frail, childish, unlucky and bad at sports. He sleeps from a standing position to a sleeping position in less than a second.

Noby's typical day consists of arriving late to school, scoring zero in his tests, getting scolded by his teacher, being teased by his classmates Big G and Sneech, falling in the curbside rain gutters, dogs running after him as he step his foot by mistake on the dog's tail, getting grounded by his mom as she receives complaints against Noby for not completing his homework, coming late to school or either his poor performance in his studies and sports, falls asleep during class, and does not have a good image between his friends except Sue, who remembers Noby's kind heart and worries about him.

Some notable personality traits in Noby are his cowardice (where he is scared of almost everything, especially ghosts) and his cry-baby (a running gag in the show has Noby crying, mostly at the beginning of the episode) attitude.