Yuusuke is an orphan living independently while struggling financially, particularly with rent. He discovers Rouge unconscious after she falls from the sky, suffering from amnesia, and shelters her. He shows practical responsibility by involving his landlady to handle Rouge's undressing instead of doing it himself. He develops a caring relationship with Rouge, comforting her during nightmares; their mutual vulnerability leads to non-romantic physical embraces. His protectiveness extends to Rouge's sisters when they arrive, despite the disruption to his life, and he actively confronts threats from their family's enemies. His orphan background shapes his actions, driving him to form a deep emotional bond with Rouge and her sisters, whom he calls his new family. He states his greatest fear is losing Rouge. The princesses' presence forces him to balance daily responsibilities with safeguarding them against interdimensional adversaries.