well as Norihiko is fucked up in the head it kind of is love in his own way. Also when he thinks about Ikuro he mentions a beautiful heart and such and how he cannot protect him. It is just that sadistic, possessive and manipulative people express their love in such a manner and the last updated chapter is a perfect example as he hates the fact that somebody did that to his loved one yet he in the end punishes the victim itself and manipulates him, intentionally or not, into thinking that norihiko couldn't have known that he wanted help and so on. Who knows wtf happened to norihiko to have made him like that but usually you have to have a trace of it naturally in your character to become like that.
Manipulation, abuse and obsession do not represent love in any way, shape or form. They just don't. Persons who are "fucked up in the head" may describe it as love but they are "fucked up in the head" so they're not exactly a reliable source.
Norihiko is treating that boy like a sex tool, as reirei said.
Manipulation and those are just personality traits of norihiko and since he is fucked up in the head he can't present his love in another way. That was what I meant to say. Also, if he was just a sex toy to him he would be off far better and norihiko would definitely not be obsessed with him then. It is far above the sexual level. It is quite clear that there would be no real interaction between them if norihiko would not have an affinity for Ikuro. Basically if such a person has no interest in something they will just push that thing aside and just don't give a fuck about it. Their psyches are interesting but have definitely been done a million times in yaoi.
Basically, Norihiko just doesn't know how to represent his love and just acts like the asshole he is naturally.
I, honestly think that Ikuro should say no to Norihiko and Honda sensei. I sense that Norihiko used Ikuro as a tool and definitely not love. It is not possessed love but just dominating. To hold political and business power was extremely the greatest. You became powerful and people willing to kneel before you.