Tsugu-chan is separated from her friends (Sora, Yuushin and Asari) when she moves away. After a few years, she finally returns and is happy to be reunited with them. Tsugu-chan believes that her friends didn't change, but that doesn't turn out to be the case.

This story begins in the paradise/heaven, where souls, before being born, can choose their mothers. The protagonist notice a girl who has run away from home, and he decides to down to earth and become his son.

The title story, “The Mermaid Prince,” told in three chapters, is a coming-of-age story set in Okinawa. The boy, Mugi, has a fascination with mermaids. He moved in from Tokyo when his sister got married to a local man, and doesn’t quite fit in. On the day he met the girl, Madori, she was just coming to terms with her new family situation. His thoughtful gesture made her view him as her Prince Charming.

In the second story, “Snowy Day,” a homeless father and son take refuge from the snow in a library. The librarian soon finds out there is more to them than meets the eye.

The third story, “Ametsukigahara,” is a two-parter about a girl named Akari. There’s not much she cares about in this world, except maybe her friendship with Fumika, who’s afraid of boys. But then Fumika gets a boyfriend, and something happens that makes Akari even more jaded than she already was.

Collection of short stories by Kaori Ozaki ("Immortal Rain"), including her debut story. The earliest story in the volume was written when she was sixteen, and the last one when she was nineteen.

It's the summer when Natsuru is 11. The girls in his class have been constantly ignoring him since he's turned one of them down on Valentine's Day. This changes just before summer break, when Suzumura, the tallest girl in his grade, suddenly talks to him. Natsuru meets Suzumura again outside of school and finds out she has a secret.

Rain Jewlitt, known as the Methuselah, is a spaced-out, immortal, 624-year-old man dressed in priest's clothes. He's got eternal youth and a large price on his head—put there by those questing after the secret of his immortality.

Machika Balfaltin is a tomboyish, energetic 14-year-old girl who, upon the death of her grandfather, sets out to kill Methuselah, the one bounty her assassin grandfather, Zol the Grim Reaper, couldn't kill. Instead, however, Machika ends up being saved by Rain again and again from other aspiring bounty hunters attacking them both.

Sound like the beginnings of an odd relationship? You won't believe where their journey takes them...

A miniseries prequel about the encounter between Rain and Zol. This is a prequel to Immortal Rain set before Machika's birth. Machika's grandfather Zol, who works as a bounty hunter by the name of Grim Reaper, encounters Rain, who turns out to be Methuselah, the most wanted man in the world. Why did fate bring these two men together and what is hidden behind Rain's clumsy and kind personality?