True. It's more of a BSS, a sub-genre of NTR. Also, Ryoka is just a loose slut as evidenced in the playboy dude's route. I enjoyed the base game and the after story but the latter doesn't feel like the product that was promised. It spread the scenes out tok much across routes and fails to address the "corruption jumps" in the base game. FFS, in Yasui's route Ryoka has one true gangbang if you ignore the ending one. She also doesn't get banged by half the class, just the same dude who did her in the base game.
Speaking strictly from a game design perspective to not derail the thread too much. SoS falls into the same trap as many other NTR games.
It introduces more branching paths than it can afford to flesh out. To any NTR devs lurking in the thread, you don't need the NTR Avengers in all your games. Having a 2 or 3 fleshed out routes with each appealing to different types of NTR fans would work. One can focus on a pure love route but with a rival, one can be a blackmail route and one can be a corruption NTR route where the heroine is turned into a cum dump.
You also don't need 9 trillion heroines (looking at you Shaman). You'd spread the scenes out too much if you do that.