Hiroko Watanabe's fiancé Itsuki died two years earlier in a mountain climbing accident. While looking through his high school yearbook, Hiroko in a fit of grief decides to write a letter to him using his old school address. Surprisingly she receives a reply, not from the dead Itsuki, but from a woman with the same name whom had known Hiroko's fiancé in school. A relationship develops between the two women as they continue to exchange letters and share memories of the dead Itsuki.

After trying to rescue a man on the subway tracks, two teens wake up in a room dominated by a mysterious black sphere that sends them to hunt down and kill aliens hiding on Earth.

Its streets overrun with children, the village of Kaname has distinguished itself with the highest birth rate in Japan. Its citizens are excited-tomorrow, the Prime Minister arrives to formally celebrate Kaname's demographic distinction. The spirit is festive, except for one 14-year-old girl. She knows the secret of Kaname's fecundity, and she's typing up a tell-all letter to a prominent journalist, revealing the crazy, complicated tale. It all began 14 years ago... Betrayed and disgraced, big-city reporter Kazuya Mizuno is banished to a desk at Kaname's boring little town newspaper. But Kaname isn't as boring as it seems on the surface. Not with characters around like Shimeko, a girl genius with a childlike lack of propriety, and her ace fisherman/folk-singer dad. Or the overbearing and unpleasant local Shinto priest, a former Christian cultist. Or Endo, Kazuya's new colleague...