The video started on the first day of filming, they hold the booting ceremony. Once filming start, the whole crew mostly stayed together for 4 months. However, the production also had a script recital which was about 2-3 weeks before the booting ceremony and they even had trainings (martial art, instruments,…) all the way up to the booting ceremony. It is unknown how much XZ and WYB were in contact before the booting ceremony, but they definitely were both at the scripts recital and XZ also joined the trainings afterwards (not known about WYB). So I just want to clarify that even though they were obviously not as close as shown in later videos, but they were not complete stranger either.
