Board Thread:Episode Discussions/@comment-1181222-20180131111324/@comment-33351429-20180131191033

Yeah, but we have seen that with advanced nature this isn't always true... For Lava Release we have at least three unrelated users (Dodai, Mei Terumi and Kurotsuchi), two for Magnet Release (Rasa and Toroi), Explosion Release is "common to members of Iwagakure's Explosion Corps"... You could argue that all of them may be related to each other, but to me it seems unlikely Looking at the "Lava Release" page, it mentions that several of the lava Release users have different forms of lava. I.e. Mei uses Acidic Mud, while Kurotsuchi uses ashes and quicklime. So it's very possible that different variations of the Release is what makes it a kekkei genkai.