From Star Strings

Synopsis

After traversing the entire planet and finding no one else, Kororu realizes that she is truly alone. While she is overwhelmed with sadness, she discovers a string reaching up into the sky farther than her eyes can see. Filled with a sense of wonder, she spends the night holding on to the string—only to awaken to a pull coming from it. When Kororu comprehends that someone might be trying to communicate with her from among the stars, she becomes determined to climb the string and meet the person at the other end. [Written by MAL Rewrite]

Anime adaptations