Lily Baker is a thirteen-year-old British girl who has recently moved to Japan and serves as the main female protagonist of the story. She is a first-year middle school student who initially struggles with the language barrier, able to comprehend much of what is said around her but lacking confidence in speaking Japanese. Her personality is cheerful, enthusiastic, and highly expressive, often mixing English with basic Japanese to communicate her excitement. She is determined and competitive, especially when it comes to arcade games, and she accepts losses with visible frustration but remains passionate about improving. Her adorable appearance and spirited nature earn her the affectionate nickname "Arcade Idol" among regular customers at the game centre.

Lily’s central motivation stems from her desire to find a sense of belonging in a new country. She initially feels isolated at school due to her limited Japanese, but her world expands after a chance encounter at the arcade on Valentine's Day. While trying to win a Brave Koala plush from a claw machine, she is helped by part-time employee Renji Kusakabe, which she misinterprets as a romantic confession due to cultural differences. This misunderstanding becomes the catalyst for their ongoing relationship. Lily becomes a regular at the arcade, and she and Renji begin exchanging a notebook to learn about each other’s cultures, forming a deep friendship that gradually develops into something more.

In the story, Lily serves as the driving force behind the cultural exchange theme. Her role is to bridge the gap between her British upbringing and Japanese society, with the arcade acting as the central meeting point. Key relationships include her bond with Renji, whom she views as both a mentor and a romantic interest; her older sister Sheryl, who is more pragmatic and protective; and Renji’s younger sister Aoi, who becomes a close friend and cultural guide. Lily also forms friendships with other regulars and staff at the arcade, including the skilled gamer Karin Kaga, who initially acts as a rival but later becomes a mentor.

Over the course of the series, Lily undergoes significant development. She grows more fluent in Japanese, eventually speaking it most of the time and even helping others as a translator. She becomes more confident in social situations, shedding her initial shyness and opening up to those around her. Her love for arcade games evolves from simple enjoyment to a competitive drive, and she learns to navigate both the games and the social nuances of her new home. Notable abilities include her quick adaptation to Japanese culture, her growing proficiency at claw machines and other arcade games, and her innate ability to draw people together through her warmth and persistence.