Shitsurengo, Kenaku datta Osananajimi Ga sato Kashi Mitai ni Amai - Sugar After Bitter

Yuu Sawatari, a high school boy, is sick after suffering a painful heartbreak. His nextdoor childhood friend, Cocoa Shirayuki, shows up to take care of him. From that day on, the distance between them grows closer... This is a tense, sweet, and slightly heartrending love story of a boy who has lost his love and his childhood friend whose love has long been unrequited. (Source: Kodansha, translated) Note: Includes two 0.5 chapters and a bonus epilogue.