The first three stories are all about obsessions of different types. It involves homicide (the 2nd story) so be warned.
Rape and Gangrape.
This story is just about Sen and Sword fucking each other and other people (by other people I mean Norman LMFAO). The extra chapter showcases Sen and Sword in a polyamorous relationship.
SEQUEL ^^^^
This story is just about the three characters (i forgot their names, sue me) having an unofficial threesome
Gangrape
Bara, Tentacles, Threesome, Rape, and a little bit of Pedophilia.
I found this funny for some reasons. Anyway, there was a notorious groper running amok in public train. Eventually, they caught the groper and... had a threesome...
Nani mo Iwanai