Ah, I can see some similarities, but I connect the sex system more with era SLGs in general rather than eraTohoK specifically.The sex system and character "development". The gameplay is vastly different, yes, but then LT has basically no gameplay to begin with anyway.
There are some huge differences though. E.g. the purpose of the sex/training system in era SLGs is to attain one of the fall states, while the system in LT barely affects an NPCs affection or obedience, if at all. The main source for those stats in your slaves is their job assignments and room accomodations. And while you can train NPCs in era games to get them to gain fetishes, in LT that's done exclusively via enchanted potions.
The only thing they really have in common is that you can choose position and act, and imho that's done better in LT, as it allows the NPC to act, too. IIRC the only way to get the NPCs to act in eraTohoK is to sacrifice your turn, while in LT they can choose an action on every turn.