What I can remember about it is that they were teacher and student?Or at least younger-older relationship. At the start, the young one is the sadist one and kepts the old one in a big cage, the masochist was looking for someone that would never leave him ,not break and 'submit' no matter what, cause his other partners always ended up submitting their masochistic side, then shows his true colors and kidnaps the young one and they switch roles and something like that the young one ends up being "the one" that would never surrender
So this manga was about this guy that returned to his house and was suddenly kidnapped and was took to this kind of abandoned place and the kidnapper was like really usseless so he needed to help him to make it to another day with him and later on in the story we find out that the kidnapper was actually kidnapper as a kid in place of this other kid that got away and the pedo actually killed himself and had a lot of photos of the uke as a kid and at the start they were like fishing¿ and remembering how they met and falled in love, kind of stockholm syndrome xd
this was very confusing I don't know if this link is going to help you.
http://www.mangago.zone/tag/Kidnapping/?page=2
F2f
He is so narcissistic and egocentrical that is ridiculous lol