Junichi Katsuragi, a charismatic senior student idolized as "Brother Jun" by Sentarou Kawabuchi, cuts a striking figure with his artfully swept black hair, brown eyes (occasionally noted as blue), and a lean, stylish frame accentuated by belts and sunglasses. Born into privilege, he abandons his Tokyo academic pursuits for political activism, a choice that spirals into expulsion, disownment, and homelessness. Battling mental health struggles and reliance on alcohol, cigarettes, and tranquilizers, he finds temporary refuge with Tsutomu Mukae.

A gifted trumpet player, Junichi’s soulful jazz performances at a U.S. soldiers’ bar captivate Yurika Fukahori, who persistently bridges his self-doubt to forge a romance. Their bond deepens as she aids his recovery, ultimately steering them toward Tokyo after he secures a journalism position. The anime adaptation reveals Yurika’s six-month pregnancy, while the manga concludes with the couple nurturing twin daughters.

Renowned for his combat skills and peer admiration, Junichi defiantly rejects inheriting his family’s "Shirayuri" café, choosing autonomy over legacy. His name, rooted in the characters for "pure" and "one," echoes his turbulent evolution from fractured rebellion to grounded resolve. Through Yurika’s steadfast support and his own determination, Junichi’s journey closes on a note of hard-won stability, embracing Tokyo’s promise of renewal.