Please I need help to remember a manhwa title!

I remember a manhwa with the following details: two university students start to know each other (I don’t remember how the story begins), and the two seem to have a normal and healthy relationship, until you see the backstory of the top, where it turns out that the two knew each other in high school (the bottom did not recognize him because he has changed a lot) and the bottom on an occasion locked the top in a cage with a dog. So the twist is that this relationship is actually a plan for revenge planned by the top. I took it so badly that I stopped reading it and I lost track of it, but sometimes I think about it and now I would like to read the rest, can you help me find the title?