@Tcof Well.. If I remember they had bad relationship problems after they started dating, (haven't read this in a minute, so I'm pretty sure, I'd have to re-read ;w
![Wink ;) ;)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
, in total a situation rises in which one of them takes their life because of it (because love) and so fourth the other does the same, or they both planned it out, or maybe the female mc did it because she was holding the knife, I don't know.
But honestly not many other possibilities I can really think of for this scenario...