Mariko Konjo is a cheerleader from Seisyun High School.
Mariko is a common Japanese name meaning "child of true benefit." This could be a reference that she benefits the teams she cheers for and ensures that they do not lose, or simply that she's vain, trend-obsessed, and used to the spotlight. Konjo is broken down into "today's law", which could also be an ironic reference to the fact that she helps her teams break the rules.

(Source: Ranma Wikia)