Ren Nanahoshi is a first-year law student at Kamogawa Music College. His full name (七星 蓮) combines the characters for "seven," "star," and "lotus," with "Nanahoshi" evoking the Ursa Major constellation. A childhood outdoor concert ignited his dream of performing, yet a negative experience in his middle school choir club confined his singing to private karaoke sessions instead of public stages.

Naturally shy, soft-spoken, and reserved, he often struggles with communication. Despite this introversion, he possesses underlying determination and strength of will, enabling decisive articulation of his thoughts when necessary. His innocence and earnestness are defining traits. An encounter at a karaoke bar introduced him to Yuto Goryo and Wataru Matoba, who were searching for a vocalist for their nascent band. Impressed by his singing, they persistently invited him to join. After initial reluctance and rejection, he agreed following their live show where he performed alongside them, forming the band Argonavis with Ren as vocalist.

Within Argonavis, Ren navigates the challenges of pursuing musical stardom, performing at major events like the Destiny Rock Festival. His proactive dedication to the band and music contrasts with his usual timidity. After transferring colleges, he shares law faculty classes with Nayuta Asahi. Outside music, he exhibits specific enthusiasms: he is an avid Super Sentai Series fan, capable of excited, lengthy discussions about it, and holds a particular fondness for Lucky Pierrot’s Chinese chicken burgers, visibly disappointed by their absence in Tokyo. Conversely, he struggles with technology, self-identifying as a "tech noob" after difficulties operating recording equipment during a band session.

His journey centers on overcoming isolation and channeling his musical passion into collaborative performance, gradually finding his voice both literally and figuratively through Argonavis.