Once upon a time, there was an immortal gray cat who was incapable of love, pain, age, and death could not touch him. The gray cat had lost his heart a hundred years ago. When the demon who had traded the gray cat a immortal life for his heart, died, the heart burnt to ashes with him. There were many various songs and legends about the immortal gray cat. Some of them told a story about a gray cat who appeared in a war and killed a lot of armored samurai with only one short sword. But the question was still haunting the gray cat’s eternal life. The question that could never be answered without a heart - his heart had turned to ashes forever or something could revive it? With his heartless immortal body the gray cat made a journey, wishing in his mind, he might find the lost gray heart or some meaningful answers to the very question that had been clinging to his eternal life:

'How did love feel like?'