SessKag? That's a pairing built entirely on defiance, which is maybe why it keeps drawing writers in. You've got the ultimate unflappable demon lord and the modern girl who won't bow to anyone, not even a daiyokai. The tension writes itself. A lot of stories lean into the 'what if' after the jewel—like, what if Kagome returned to the Feudal Era not for Inuyasha, but because her modern life felt hollow? I've read a few where Sesshomaru, post-character development, finds her lingering presence a puzzle he can't solve, and that slow erosion of his indifference is the whole point. It's less about romance and more about two immovable objects learning to orbit each other.
Then there's the whole 'shared guardianship of Rin' angle, which is a classic for a reason. It creates this forced proximity scenario that feels organic to the canon. They have to communicate, they have to negotiate, and suddenly you're five chapters deep in a domestic AU where Sesshomaru is begrudgingly learning what human children need for dinner. The appeal is in the subtle shifts—a glance held a moment too long, a strategic intervention she doesn't even know about. The popular themes are all about bridging that immense gap: time, species, social hierarchy. You see a lot of 'Kagome gains power' stories too, where she becomes a miko of such caliber that he's forced to acknowledge her as a peer. That power-balance correction is a huge draw.