Humans have been writing stories before they could even literally write (verbal lore). So no, it's not original. If you dig long enough, someone most likely has already done it. So stop complaining about originality, it's practically impossible to be original. Also the whole perspective of originality is subjective. For someone who has never read manga or even exposed to yuri this is the most fly bat sh*t original graphic representation of a plot they have ever come across. Even the artist them self may think it's a original idea because THEY have not come across it.