Mari Tamaki, who goes by the nickname Kimari, is a sixteen-year-old second-year high school student and one of the main characters of the story. She has neck-length light brown hair cut into a bob, hazelnut eyes, and a youthful, expressive face. She stands 155 centimeters tall and lives with her parents and her younger sister Rin. Mari is bright, energetic, and full of curiosity about the world, but she struggles with indecisiveness and a lack of follow-through. She entered high school with the vague aspiration of making the most of her youth, yet she often finds herself unable to take the first step toward anything substantial. Her fear of the unknown and anxiety about her own limitations hold her back, leaving her frustrated with her own inaction. Her motivation shifts when she encounters Shirase Kobuchizawa, a classmate who has been saving money for years to fund a trip to Antarctica in search of her missing mother. Inspired by Shirase’s unwavering resolve, Mari impulsively decides to join the expedition, viewing it as a chance to finally do something meaningful with her youth. This decision sets the entire story in motion and marks the beginning of her transformation. In the group, Mari serves as the emotional center and the catalyst for action. She is sensitive to the feelings of others and often helps her friends open up about their own struggles. Her kindness and empathy allow her to connect deeply with each member of the team. She relies heavily on her childhood friend Megumi Takahashi at the start, but over the course of the journey she learns to become more independent. Mari’s relationship with Shirase is central: Shirase’s determination pushes Mari to confront her own fears, while Mari’s warmth helps Shirase come out of her shell. With Hinata Miyake, Mari finds a friend who balances spontaneity with practical advice, and with Yuzuki Shiraishi, she gains a new perspective on friendship and social bonds. Throughout the series, Mari undergoes significant development. She transforms from a timid girl who avoids risk into someone who actively chooses to face challenges. Key moments include her decision to go to Antarctica despite her fear, her struggles with the harsh environment, and her growing understanding that taking action, even when scared, is the only way to truly live. By the end of the expedition, she has gained confidence and a sense of purpose that she previously lacked. Mari does not possess any supernatural abilities or combat skills. Instead, her strengths lie in her resourcefulness, optimism, and ability to motivate those around her. She has a knack for problem-solving and organization, helping to plan logistics for the journey. She also displays an unexpected talent for games and observation tasks during the Antarctic mission. Her emotional sensitivity, while often an asset, can sometimes lead her to push herself too hard or become overwhelmed when things go wrong. Nevertheless, her growth into a more decisive and resilient person is a core part of her character.