18-Volt is a major human character in the WarioWare series. He is 9-Volt's best friend and are both classmates. He has a very large stature and appears to be a teenager. His precise age is left unclear for most of the series, but in the French, Spanish and German dubs of WarioWare Gold, he states that he is 9 years old. Although 9-Volt and 18-Volt both appear to share the same love of Nintendo video games, 18-Volt seems to be more inclined to music, as WarioWare Gold reveals his main interest is in rapping.
18-Volt arrives as a new student at Diamond City Elementary. When the teacher asks him to describe himself to the class, he takes up his favorite hobby: playing loud music. Which makes the master angry.
As 18 Volt walks home with an angry pout, 9 Volt asks him if he can hang out at his house and 18 Volt agrees. 18-Volt takes a tour around the house and 9-Volt gets him to play along with the Nintendo Entertainment System.
They play together for a long time, until 9-Volt's mother, 5-Volt, sends 18-Volt home and 9-Volt to bed.
WarioWare: Smooth Moves[]
9- and 18-Volt buy a game called 36-Volt Man at their local game store and play 9-Volt's House. They win and party until they fall asleep late at night. They wake up in the morning and are horrified looking at the clock that they are late for school.