Tsuki wa Higashi ni Hi wa Nishi ni

Tsuki wa Higashi ni Hi wa Nishi ni: Operation Sanctuary (月は東に日は西に -Operation Sanctuary-) is a Japanese adult visual novel developed by August. It was released on July 20, 2003 for Windows until it was ported to The Dreamcast and PlayStation 2 versions by Alchemist in 2004. An anime adaptation broadcasted in Japan which ran from June 30 to September 22, 2004. The series has produced a manga adaptation by ASCII Media Works that was serialized in Dengeki G's Magazine, multiple light novels and several drama CDs by Geneon Universal.

Plot
Naoki Kazumi is a boy who had amnesia after his parents died in an accident five years ago. Since he had nowhere else to go, he lives with his cousin Matsuri Shibugaki and her parents. Every morning before school, he is awakened by his childhood friend, Honami Fujieda, who keeps telling him that he is not a child anymore, but still comes to wake him up. These usual, ordinary days seem to stretch on forever, until one day up on the school's rooftop, while Naoki is taking a peaceful nap, out of nowhere, a girl falls out of the sky. This girl, called Mikoto Amagasaki, comes from 100 years in the future, and she went back in time with the intention of finding her brother. When Mikoto sees Naoki, she mistakes him for her brother.