Help with finding this title

I can’t remember the name but Seme basically isolated Uke from everyone so he can really rely on seme a lot. Seme is verry obsessed and possessive over him. To the point he even cause uke’s parents to die in a car accident which traumatized uke a lot. Not sure if it’s omegaverse type or what but the ending goes with them being together, seme being happy to all the things he have done in the shadows and it also showed the actions he took for uke to be dependent on him on the ending. There also a giant aquarium with 1 beta fish on their house. I think He was doing a metaphorical example of how beta fish are territorial just like him. Can’t remember any physical traits of the characters and plot. All I remember is it’s giving a sweet cage vibes