In order to save her best friend Shiro's life, Kuro transplanted her own heart to her. In exchange, Kuro had to attach a "mechanical heart" that required charging to stay alive. Years after the surgery, the two struggle to adapt to their new hearts, and their doctor hands them a certain device...? The title story "Heart's Gift" is included, along with two other popular short stories, "Two Spirals" and "The Job Hunt of the Immortal Human - Resurrection!" Additionally, the elusive extra chapter "Heart's Gift - The Day Before the Date," which was only published in a doujinshi, is fully included! With fresh yet sharp depictions that captivate readers, this is the long-awaited first collection by the author, who shines with a unique brilliance!