Zashiki Warashi is a child ghost which is supposed to bring good fortune to the house or building it appears in. They are know to play tricks. Once they leave the house, the good fortune is supposed to leave too.
A friend of mine works for an English school here, in Sapporo. His school has numerous classrooms all over the city. Apparently one of the classrooms is supposed to be occupied by a spirit. One of the Japanese ladies who teach English at the school reported that her keys go missing, and then reappear later where she left them.
My friend had to conduct trial lessons for the school (conducted once a year, when existing students (kids) can introduce friends or other kids to the lesson. Apparently 5 to 8 introductions is high. The first school he visited that day had no students. The second classroom had 3 existing students, and no introductions. The third classroom (the supposedly haunted one) had 3 existing students and 16 trial students! He conducted the lesson, gave all the students candy and then handed out forms for them to fill in (name, whether the lesson was fun or not). A photo was taken and the students counted by himself and the two Japanese ladies who worked with him that day, 19 students…
He went home and later received an e-mail from one of the ladies. She wrote:”otsukare sama, arigato, but only 18 forms were counted” 19 kids but only 18 forms…
Of course, one of the children could have forgotten to fill out a form or was missed out when the forms were handed out, but there is a chance somebody was playing a trick on that day…
