I’ve written before about how ambitious British and American graduate recruits do their best to stand out from day one, while ambitious Japanese recruits try to blend in, with the “recruits suits” that are even more conservative and standardised than usual being part of that. Given the width of the blouse collars in April, however, I think there might be more to it than that.
It also occurs to me that they (subconsciously) want to point out to everyone in the company that they are new recruits. That could help them get a little patience and maybe even instruction when they are stuck in a department and expect to pick up a job through osmosis. More importantly, though, it could help them bond with the people who were recruited at the same time who will be their natural allies (along with people from the same school and university) through the rest of their careers.