Matthew Williams is a boy with Severe Combined Immuno-Deficiency Syndrome, better known to the world as Bubble Baby Disease. He's been raised by his brother, Arthur all his life, and hasn't even met his brother, Alfred. So, a boy comes in and rents out a room in the house, and nearly kills Matthew by touch. After that, the boy, Gilbert, swears he will make it up to Matthew. How? With love. And Matthew... just doesn't mind.