[Nov 16th Edit: This has been in my drafts for a while. You may or may not already agree that the opening statement has happened. I repeat the it with the emphasis on unequivocal proof, e.g. love confessions, public admissions of a relationship, and/or explicit on screen kisses.]
I’m going to start by making a bold claim: that the sports-genre anime Yuri!!! on Ice will feature a canon (textual) same-sex couple. I would bet money on it.