Futari

Chizuko and Mika are sisters who get along very well and have a good relationship, but one day Chizuko dies unexpectedly in an accident. Mika always feels undermined for not living up to her sister's achievements until one day, the ghost of her sister appears again. And by the encouragement of Chizuko, she overcomes various difficulties in her life.
~~ Adapted from the novel "Futari" (ふたり) by Akagawa Jiro (赤川次郎).