Rossiu is a boy from another underground village where the inhabitants revere Gunmen as deities. When Gimmy and Darry are selected to depart from the village, Rossiu opts to accompany them, and they all join the Gurren-dan.
Rossiu adheres to choosing the most rational and sensible path when confronted with issues, a stance that often clashes with a world not governed by logic or reason. His logical approach frequently leads to disagreements with other Gurren-dan members, who view his perspective as defeatist or cowardly.
