Eriko, a purple-haired member of a trio serving under a high-ranking alien officer, aids in recruiting a retired musician to resolve an interstellar war. Known for their bumbling antics and comical misinterpretations of human customs, the trio frequently derails missions through misguided schemes or reliance on dubious rumors. Tasked with logistics, surveillance, and mediating interactions between alien forces and the musician, their ignorance of human behavior sparks recurring chaos.

Their assistance takes bizarre turns—orchestrating staged scenarios to nudge the musician toward cooperation, only to trigger chaos or unintended fallout. Though their actions inadvertently propel the alien military’s agenda, their true purpose lies in providing levity, highlighting their wide-eyed naivety and clumsy execution of even simple tasks.

Eriko’s history and motivations remain undefined beyond her function within the group. Her presence strictly serves the core storyline, with no expanded exploration in official media or adaptations.