Hajime, an only child who grows up feeling set apart from others, forms a deep bond in childhood with Shimamoto, a quiet girl who shares his sense of isolation. Their connection is intense but brief, ending abruptly and leaving a lasting imprint on him. As Hajime moves into adulthood, he builds a stable life—marrying, raising a family, and running a successful jazz bar—yet he carries a persistent sense that something essential is missing.

Years later, Shimamoto reenters his life, unchanged in her quiet, enigmatic presence. Their renewed connection awakens long-suppressed feelings, drawing Hajime into a relationship that blurs the boundaries between past and present, reality and longing. As he becomes increasingly absorbed in her world, the stability he has built begins to feel fragile.

Subtle and introspective, South of the Border, West of the Sun explores desire, memory, and the illusions people construct around love and fulfillment. It is a story of emotional reckoning, where the pull of the past challenges the life one has chosen in the present.