When Masami's father died, he was told by his grandfather that he had to move out. In order to find a new place that he could live in for 80,000 yen a month, he asked his unrequinted love "Kagome" to look for a new place for him. But unfortunately, because of that, he has had to join the "extremely normal phenomenau observation society" that she founded. And on top if it, there are rumors that things seem to "appear" at the things that the she finds...
Published in 1999 through 2001, there are 3 volumes to this series.
This is a song, used in a children's game. In the game, one child is the "demon", and is blindfolded in the center of a cicle. All the other kids join hands, and walk around in a circle while singing the song. When the song ends, the "demon" calls out the name of the child behind him or her, and if s/he is correct, that child becomes the new "demon". The turtle and crane together symbolize something good, but since they have slipped, something bad has happened. Many thanks to this site for a nice explanation of Kagome, Kagome (in Japanese.)
The song is reproduced and translated on the table of contents of the first volume.