Franck Latoine is a French piano student who plays a supporting role in the European arc of the story. He resides in a music student-friendly apartment complex in Paris, the same building where the protagonists Shinichi Chiaki and Megumi Noda, known as Nodame, come to live. Franck first encounters Nodame during their entrance examinations for the prestigious Paris Conservatory, where they form an initial bond over shared snacks, revealing his friendly and approachable nature.

In terms of personality, Franck is distinguished by his unabashed enthusiasm for Japanese anime culture, identifying strongly as an otaku. This passion is a central part of his daily life; his room is decorated with anime figurines, and he meticulously programs his schedule to record new episodes of his favorite series. He often wears clothing featuring anime characters, a habit that others occasionally find irritating and which tends to hinder his social interactions, particularly with women. His particular favorites include the series Shakugan no Shana and a fictional magical girl anime titled Puri Gorota, which coincidentally is also Nodame's favorite show. His appearance is that of a young adult, characterized by blond hair and blue eyes.

Franck's motivations are rooted in both his social desires and his musical ambitions. Upon reuniting with Nodame in Paris, he develops a slight romantic interest in her, interpreting their encounter as a sign of fate. He makes an effort to impress her, notably by cleaning his room and inviting her for tea. However, this interest wanes after he witnesses the depth of her own anime obsession, as she is able to recite entire episodes of Puri Gorota from memory in French. He concludes that her enthusiasm surpasses his own, and he also recognizes her strong existing connection with Chiaki. Musically, his ambition is to study under the admired Professor Charles Auclair. He transfers to the Paris Conservatory specifically for this opportunity, having previously attended the same school as another student, Yunlong.

Franck’s role in the story is primarily that of a friend and neighbor to the main characters. He provides a sense of community within the apartment complex and shares a common interest with Nodame through their mutual love of anime. His key relationships include a friendly rapport with Chiaki and a significant dynamic with Tanya, a Russian pianist who also lives in the building. Their interactions often consist of mutual complaints and cultural observations, and Franck is sometimes enlisted for practical tasks, such as helping with computer setups. Over the course of the narrative, Franck demonstrates noticeable development as a musician. His abilities grow to the point where he earns an opportunity to perform chamber music with the accomplished pianist Rui Son, a development that hints at both his artistic progress and a potential new romantic interest. As a pianist, his abilities are respectable enough to gain him entry to a top conservatory and to grow significantly through his studies, even if he is not portrayed as the same calibre of prodigy as some of the central characters.