Ichigo and his inner Hollow? That dynamic's a playground for writers, honestly. A lot of stories lean hard into the forced cohabitation angle—two beings sharing one body, stuck with each other 24/7. It naturally breeds conflict that can tip into weird intimacy. You see a ton of 'there's only one bed' scenarios, but mentally. Like, they're forced to merge consciousness to survive some threat, or Ichigo gets injured and Hichigo has to take over and keep them alive, which leads to some seriously complicated caretaking. The enemy-to-lover pipeline is strong here, but it's less about romantic dinners and more about raw survival bonding.
Then there's the whole identity crisis plots. Who's really in control? Is Hichigo just a darker part of Ichigo, or is he his own person? Fics that explore that often have Hichigo manifesting physically somehow, and the two of them having to navigate the world as separate but eternally linked entities. The popular twist is Hichigo getting his own gigai or being pulled out by a mysterious artifact, leaving them both to figure out what they are to each other when they're not fighting for dominance every five minutes. Those fics tend to get philosophical, sometimes slipping into existential horror, which I'm totally here for.
A niche but persistent plot I've stumbled on is the 'Hichigo was there first' trope. The idea that the Hollow essence was always part of Ichigo's soul, predating his Shinigami powers, and Zangetsu just… managed it. That flips their dynamic completely and makes for some heartbreaking retrospection. You don't see it as often, but when it's done well, it hits harder than Getsuga Tenshou.