Follow Your Heart plot
Mary lives in a world where people's hearts live on the outside of their bodies, acting like pets they love and bond with. These hearts are a reflection of their owners, but they can also be easily lost in life's struggles. When Mary suffers a romantic disappointment, her heart begins to languish. Both become despondent and lose their zest for life. When this bottoms out, Mary loses her heart, making life flat and boring. But Mary begins to find her way back through reconnecting with life and is soon reunited with the most precious part of herself - which has also been on its own journey, seeking its own happiness.