Marina Kirarazaka is a schoolmate of Shizuka Kuze and serves as the main antagonist in the narrative. She is a young student with long blonde hair, often styled with a headband that reveals her forehead. On the surface, Marina presents a cheery and upbeat demeanor at school, which contrasts sharply with the brutal words and actions she directs toward Shizuka. This facade of popularity and friendliness masks a deeply troubled interior. Her hostility toward Shizuka is rooted in her own complex and painful family background. Marina's father engaged in an affair with Shizuka's mother and subsequently abandoned his family, an event Marina blames on the Kuze family. At home, Marina is subjected to emotional and physical abuse from her mother, who is struggling with her own despair and dependency issues. This creates an environment where Marina is both a victim and a perpetrator, embodying a cycle where abuse is passed from one person to the next. Her motivations are driven by misplaced hatred and a desire for revenge, as she projects the anger she feels toward her father and her circumstances onto Shizuka, who becomes a target for her pent-up resentment. Marina is not simply a one-dimensional bully; she is a tragic figure whose aggressive behavior is a manifestation of her own suffering. She is manipulative and strategic in her cruelty, using both psychological intimidation and physical violence to torment Shizuka. Her role in the story is central to the exploration of themes such as the perpetuation of emotional abuse across generations, the difficulty of breaking the cycle of victim and perpetrator, and the profound impact of parental actions on a child's development. Her actions serve as a major catalyst for the plot's tragic and time-loop events. A key relationship is with Shizuka, whom she sees as the cause of her family's unhappiness, but her interactions with her abusive mother also define her, as she both fears and desires love from her. With the alien character Takopi, Marina reacts with suspicion and aggression, viewing his interventions as a threat. Her dog is her only source of genuine affection. Throughout the story, Marina demonstrates a sharp wit and considerable skill in emotional manipulation. Her boldness and strategic nature allow her to maintain control in social dynamics, yet these traits are a mask for deep insecurity and paranoia. Although she appears confident and commanding at school, she is actually fragile and deeply wounded. In alternate timelines, moments of vulnerability are briefly exposed, hinting at a potential for change if her underlying trauma were addressed. Her development highlights how anger and projection can turn children into agents of harm, and her story raises questions about responsibility and forgiveness.