Meiko "Menma" Honma, a cheerful and kind-hearted girl who tragically drowned at age ten after chasing a friend, reemerges years later as a ghost visible only to Jinta Yadomi. Clad in the white dress from her final day, now barefoot from the accident, her spirit retains youthful speech yet shows subtle signs of aging. Her unresolved wish—initially obscured by fragmented memory—drives her to mend the fractured bonds between her estranged childhood friends, whose guilt and grief scattered them after her death. Though a ghost, she interacts tangibly with the world: opening doors, preparing meals, and leaving traces like lingering scents or an oppressive air sensed by others.

Selfless and emotionally attuned, Menma prioritizes others’ pain over her own, shedding tears for their wounds but seldom her plight. Her childhood crush on Jinta surfaces in a poignant final letter expressing a desire to marry him, while her protective instincts echo in memories of urging her younger brother Satoshi to safeguard their home. Years after her spiritual departure, her friends pen letters to her as part of their healing, resuming school, work, and confronting buried insecurities. A decade later, a tradition of annual gatherings hints at her possible reincarnation, symbolizing enduring legacy over loss.

Her name intertwines with her fate: "Menma" blends syllables from her given and family names, evoking both a pickled bamboo shoot and the Latin "amnem" (river)—the site of her drowning. "Honma" signifies "origin" and "space," while "Meiko" translates to "bud," "garment," and "child," weaving themes of growth, memory, and transience into her story.