Pain, Pain, Go Away is a novel by Sugaru Miaki, also known as Fafoo, author of Starting Over and Three Days of Happiness. Unlike Miaki's previous two books, Pain, Pain, Go Away is not a rewrite of any story posted to 2ch, but an entirely original one. The plot involves a young man who becomes a killer (by accident) but his victim has the power of "postponement," temporarily delaying her death.
Three Days of Happiness is a novel by Sugaru Miaki, also known as Fafoo. It's a rewritten version of the story originally posted to 2ch. The premise of the story revolves around a shop where one can sell away the remaining years of their life, and the consequences of doing so. "I Say A Little Prayer" is a short related story which was posted along with the novel's release. It spoils some things about the main story, but nothing major.
The story is about a boy entering high school, who answers a strange call from a public phone one night. The caller challenges him to a bet: She'll remove the birthmark which he sees as the cause of so many problems, and he'll have fifty days to win the heart of a girl he'd considered far beyond his reach. And with this, a very strange summer begins.
The story is about a man who's opposed to the now-common practice of implanting false memories, but is one day given memories of a fictional childhood friend. This fabricated happiness torments him, but then, to his surprise, he meets her a girl who shouldn't exist.