Ouendan is a Japanese rhythm game series, where the players play the part of an ōendan (a Japanese cheerleading squad, essentially), inspiring people in difficult situations, and occasionally saving the world, to the accompaniment of J-Pop songs. The series consists of two Japanese games Osu! Tatakae! Ouendan (literally "Go! Fight! Cheer Squad") and sequel Moero! Nekketsu Rhythm Damashii Osu! Tatakae! Ouendan 2 (literally "Let's Go! Hot-Blooded Rhythm Spirit: Yeah! Fight! Cheer Squad 2"), usually just called Ouendan and Ouendan 2 for short. The series inspired western equivalent Elite Beat Agents, which adapted the lead characters into a team of cheerleading Men in Black, and featuring western music and stories. There is also an open source game Osu!, which allows people to create and share their own levels inspired by the gameplay of the series.
Heather and Ian have played all of the games in the series, at various times, on Rhythm Cafe and the series that lead to it.