Itoshi Sae's life is just like any other. He's breathing, moving, talking and feeling. Nothing out of the ordinary. But there's one difference: Sae's got a disease, he's suffering from cancer. Thyroid cancer to be exact. Sae's been staying in a hospital in Tokyo for years now, he can't go home at the moment, because his disease has gotten worse recently.

But one day, Ryusei, another patient shows up and makes Sae's life way brighter and funnier than it actually is.