Furenai Koibito

From Atelier du Noir Scans:

Youko has a protector in Shige-san. He has guided her, helped her, and always maintained a respectful propriety since she was a little girl. The difficulty is that Shige-san is a ghost, a poltergeist who only communicates with her by throwing small rocks to signal his disagreement or to show her what to do. But now that Youko is beginning to feel the first stirrings of young love, will Shige-san’s guidance help her find her true happiness?

Note: Won the Spring 2016 Four Seasons Award (Kodansha) in the one-shot manga category.