Free Soul (YONEYAMA Kyuyu)

From DMG:

Chihomi is a starry-eyed and impressionable high school girl working part-time at Coffeehouse Itoh. When part-timer Satoshi Nagatomo comes to work at the shop, Chihomi falls helplessly in love with him. Despite her advances, Nagatomo is shy and reluctant to open up, apparently trying to hide something about himself. The proprietor of the shop, Mr. Itoh, a middle-aged man with a sharp tongue and a heart of gold watches these events unfold until one day a startling and unexpected truth is revealed...