Sumaho-chan is a Mexican girl whom Nohara family first encounters in Mexico. She lived in the neighbourhood of the Nohara family's new house. Her real name is Francisca. Due to her adolescence, she has a bad mouth, is shy as well as moody. She is given this nickname by Shinnosuke, as she always cherishes her smartphone, holding it carefully while walking, and refusing to tell Shinnosuke her name. Her parents were preyed on by the killer cactus.

Spoiler

In the final battle, she went to open the tap of the water tank pipe. She was reunited with her parents after the cactus had died.

(Source: Crayon Shin-chan Fandom)