"Little Girl Kiss" centers on the life of Itsuki, a high school student who finds himself entangled in a peculiar and emotionally complex situation. After the sudden death of his older sister, Itsuki is left to care for her young daughter, Yuzu, who is only five years old. The story explores the challenges and responsibilities Itsuki faces as he adjusts to his new role as a guardian, balancing his school life with the demands of raising a child.

Yuzu, still grieving the loss of her mother, forms a deep bond with Itsuki, relying on him for emotional support and stability. The narrative delves into their evolving relationship, highlighting the struggles of single parenthood and the emotional toll of loss. Itsuki’s friends and classmates also play significant roles, offering both support and occasional misunderstandings as they navigate the complexities of his new responsibilities.

The manga examines themes of family, resilience, and the impact of grief, portraying the characters’ growth as they confront their emotions and adapt to their changed circumstances. Itsuki’s journey is marked by moments of tenderness, frustration, and self-discovery, as he learns to prioritize Yuzu’s well-being while grappling with his own feelings of inadequacy and sorrow. The story avoids sensationalism, instead focusing on the quiet, everyday moments that define their lives, creating a poignant and relatable portrayal of familial love and perseverance.