Diabolik Lovers is the embodiment of what people call rape culture.
Simply don't watch it. This anime has nothing good to offer.

Some people may call it a guilty pleasure, but there is nothing likeable in this at all aside from the decent (and pretty standart) animation.
Gosh, I don't even know how someone got away with making this, and the worse is that it is targeted to teenager girls.
Okay, first let's talk about the (nonexistent) plot.

Synopsis(from wikipedia): The main heroine, Yui Komori, was just a normal teenage girl in high school until her father, a priest, went to travel overseas for work. As a result, Yui is sent to a new town and arrives alone at a mansion where she was told will be her new home. At the mansion, no-one greets her; however, the door swings open on its own accord. To her shock, six young men gradually appear. Yui soon notices something different about all of them: she discovers that all six of them are brothers, but by three different mothers, and that they were all vampires from the very beginning.

Okay, I never expected a complex plot or anything, I was there for hot anime vampire guys. But oh my god, this anime has NO PLOT at all, only abuse.
Yeah, that is it. The only thing it happens in the whole thing is the protagonist being verbally, physically and sexually assaulted repeatedly and multiple times.
It feels like a never ending wattpad fanfic made by a masochist.
None of these brothers have any redeeming qualities, all of them are filthy abusers that I hate with a burning passion.
Laito, the one with the hat, specifically triggers my flight or fight response every time he is on-screen. WHAT KIND OF NICKNAME IS BITCH-CHAN !?

You would think that the anime frames abuse as a bad thing right? But no. It completely romanticizes it and treat all the times the protagonist says 'no' as 'secretly into it'
Thanks! I fucking hate it
The worse is that all this shit is teaching teenager girls that being touched without consent is sexy.
Abuse !! it's !! not !!something !! romantic!!! Women being treated as sex toys is not remotely acceptable, it should be common sense by now.

And they try to humanize the abusers by giving them crappy backstories. SHUT THE FUCK UP, THEY ARE STILL ABUSERS.

In the second fucking episode one of the brothers literally throws her into water trying to drown her but suddenly has a stupid flashback.
Only to jump in the water after to bite and kiss her. It's so cringy.

If you haven't realized until now, there is not one thing I like about this anime. It's just a piece of shit abuse fantasy.

The protagonist is bland and stupid, the brothers that were supposed to be hot are all abusers that don't know what consent is, the plot doesn't exist, the animation is mediocre, the intro song is literally called MR. SADIC NIGHT or some edgy shit like that.
I simply hate every little thing and detail about it in every single way possible.

Hands down one of the worst animes I have ever seem.
Please don't watch it under any circumstance