Wicked City - WTFery?

I have been wanting to read this book since I learned of it a few years back. In the 90s I watched an anime titled Wicked City. I loved it. It was strange but the entertaining. I was curious about the light novel upon which it was based.  I have it now. And here is the review.

Taki, our hero is a fabulous guy with a fabulous life.
He works for the sooper sekrit  Black Guardand an ordinary electronic company. He has two bosses but they occupy the same office so he doesn't have to make two trips. As a Black Guard he protects mankind from malevolent demons using highly developed psychic powers.
He is so fabulous, that he is given the once in a lifetime opportunity to escort the famous Guiseppe Mayart, a lecherous hermit. The upcoming Peace Treaty signing requires Mayart's presence. Teamed with Maki, a Black Guard from the demon side, they traverse Tokyo communities, bars, parks, subways, streets, and strip clubs  with Mayart in tow. Often dragging him out of dangerous locations and away from murderous demons who want to make meals out of humans not peace.

We learn about the demons through Taki's first person narration.  It seems that our mythology has been an attempt by our human minds to frame demon interactions. For example, centaurs, the Minotaur and Kirin were all demons. From the demons, humans learned magic and gained power from us the demons ate well or emigrated to our land. Throughout the ages treaties have ensured peace and emigration but to keep all the players in line the Black Guard was formed.
In some ways the book is full of ludicrous examples of perversion and misogyny. There are some scenes in the book that make it not appropriate for younger readers.
Black out inducing orgasms. Soul absorbing demons. Rape. Vagina Dentata like you have never seen.  Mayarts overt desire to have sex with everyone he meets  and in every place he enters. And finally, Taki's inexplicable sexual desire for Maki during horrific events would confuse a younger reader. At least it should certainly disturb one. 

The novel was written in the 1980s. I had to keep that in mind while I read it. Today, I would expect more gratuitous sex and unnecessary violence.  More kick-assness from the female lead and a more conspiracy laden back story for the Black Guard. It is a quick read,  even with the WTF moments.
I give it a C+