|"Is this all real? Or has this been happening inside my head?"
The topic of this article is of a real-life subject that has been mentioned "in-universe" in a canon source. The Harry Potter Wiki is written from the perspective that all information presented in canon is true (e.g., Hogwarts really existed), and, as such, details contained in this article may differ from real world facts.
The Scotland national rugby union team (or simply the Scottish rugby team) is the team that represents Scotland in international rugby matches.
The team had their first match, which was also the first international rugby match in history, on 27 March, 1871. The match was held between Scotland and England in Scotland's capital of Edinburgh. Playing for Scotland was Angus Buchanan, who was secretly a Squib and member of the Buchanan family who had been ostracised by his Squib-hating father. Angus scored the first try, and ultimately the match was won by Scotland.
Sometime afterward, after Angus's autobiography My Life As A Squib became a worldwide bestseller, wizarding interest in the Scottish rugby team grew, with many wizards finding both respect for and sadistic enjoyment of Muggles willing to engage in such a brutal sport without the assistance of magic.
The Wizarding Supporters of Scottish Rugby Union was founded shortly after Angus's death, and serves to promote wizarding appreciation of the Scottish rugby team. There is also a persistent rumour among the magical community that the WSSRU has a secret agenda to smuggle talented Squibs onto every Scottish team. Modern suspects have included Kelly Brown, Jim Hamilton, and Stuart Hogg.