The "coat number" portion of the keyword likely refers to a specific product code or style number assigned to a costume item. In the context of anime merchandise, product numbers are commonly used to:
Our deepest breakthrough came from a cached Russian forum, ForumCity.ru . A user named "Akvarium_20" posted a single image in 2014: a photograph of a torn coat check ticket, stained with seawater. The ticket had a handwritten stamp that read: — "Water Prince - verified." coat number 20 water prince verified
