We have a report from the Relief Committee of Japan Evangelical Alliance. There have been no damage for churches in Ibaraki and Tochigi prefectures so far. Some Christian houses in Joso city were damaged and they already evacuated.
Here is a video of Joso city on Mainichi newspaper’s website:
http://mainichi.jp/english/english/newsselect/news/20150910p2a00m0na007000c.html