Normally, for my research area, a submitted manuscript is first checked by the journal through a so-called technical check to ensure there is no any obvious plagiarism issue. They use some software like turnitin with a massive database to do the comparison.
In my University, even the unergraduate's assignment report is first screened by turnitin prior to being checked by us. What a laugh that Riken even does not have such a function or hire the staff who are in such a low scientist moral.
All ends up with a big mess by this tricky lady.