It's one of the least popular ships in DMMd for somewhat obvious reasons:
1. Ren has the appearance of a dog for most of the game, and you only get to see his human-form's face when you reach his route (which has to be completed after everyone else's!).
2. When Ren *does* take form in a human body, it's Sei's.
3. Since Ren was a part of Aoba's consciousness, people deem their relationship to be auto-sexual.
I think the creators of DMMd know this, deliberately trying to make the reader/watcher think about the meaning of true love and the philosophical aspects of one's "being" by setting up these obstacles.
Ren's appearance as a dog for most the game
I particularly mean the word "appearance" because Ren was never actually a dog. Allmates are artificial intelligence systems, i.e. computers. Some of them look like pets just to appeal to Allmate-users who want that.
Compare this with Clear, who is a robot that looks human--yet people don't find much trouble with this because Clear acts very human and, most of all, looks very human.
Yet Ren doesn't receive the same treatment because people associate the sight of Ren as a dog with Ren's actual being. But Ren indeed acts much more human than dog-like.
Other than Ren's little dog-like quirks such as sniffing unfamiliar objects, Ren is actually more "human" than any of the characters of the game because he is "Restraint" or the "Superego," a tier of subconscious that animals lack.
A funny comment I keep finding on the internet is, "Why did they make the dog hot?!" Because DMMd wants you to grapple with this idea of what "Ren" is. You're making a judgment on someone's identity based solely on their looks, which leads to complications--perhaps it's not the best thing to do if you want to understand them.
Ren’s body or Sei’s body?
I really enjoyed how one of Ren’s good endings in DMMd: reconnect directly addressed this problem. It must have been damn important to the DMMd creators because it took up more than 20 minutes of Ren and Aoba feeling really uncomfortable and getting past that conversation.
Here’s a few things that were established:
Sei’s body changed after Ren’s consciousness was planted into his body. Ren grew several inches taller, changed hair and eye color, and gained more muscle than Sei ever had.
Sei probably understood the relationship between Ren and Aoba and still gave Ren his body.
Sei probably wanted the two to be happy, which is why his body was a gift.
Having realized those three facts, Ren and Aoba proceeded to have hot, passionate smex.
This is, I think, another discrepancy that DMMd wanted to throw at us to make us think: if two people love each other a lot, isn’t that enough already? Why should society’s perception of physical means restrain the true feelings between two people? I hate to draw such a parallel, but society finds disgust in the love between Ren and Aoba like some people find disgust in homosexuality.
“But incest isn’t the same as homosexuality!”
That is true, but both have are deeply rooted in biological instinct: they both don’t help with procreation or healthy babies. Because of this, they tend to become social stigma. I’m not saying they’re the same thing, but rather they are rooted similarly but treated differently.
DMMd does seem to dampen this squeamish idea, though, by having Ren’s body not be exactly like Sei’s body—maybe one can say his body is recycled out of Sei’s, like the idea of reincarnation—and having the idea that Ren, Sei, and Aoba were all originally test-tube babies. Which brings me to my last point…
This is the HUGEST point that, when people fail to understand, frustrates me. The entire point of Ren’s route was the realization that Ren is no longer Aoba! And not understanding that leads to Ren’s horrific bad end; I think it’s pretty clear that DMMd wanted people to understand that Ren has become a person of his own volition!
I find the philosophy behind this point is beautiful: what distinguishes one person from another? I’m not going to shoot off on a tangent and quote European dead guys, but I did bring up that question to tie in a huge theme that DMMd has: free will.
To be able to protest, to be able to think for oneself, to be able to fight, to be able to love someone else, to be able to make one’s decisions has been a recurring theme in DMMd. For example, Aoba loses free will whenever he resigns to his fate in any of his bad endings. Another example is Noiz’s regaining of free will from loneliness when he opens himself up to emotions and trust.
Ren’s bad ending pretty much explains that when Ren is denied to be his own being, he sees two things: (1) he must merge back into Aoba, which technically can’t be done (which is why he tries to eat him) and (2) his love for Aoba is irrational, unhealthy, and nonsensical. But this is what DMMd does not want you to think.
Instead, DMMd seems to say that Ren has his own personality (one very different from Aoba’s), with a unique face, with his own thoughts and emotions, with the freedom to resist Aoba if he wishes to.
Interestingly enough Ren once being from Aoba can be seen in a metaphorical way. One can say that, if Ren were a piece of Aoba, they complete each other. Isn’t that what the idea of true love is? Does it take into account of physical means?
Ren is inexplicably tied to Aoba because he loves him—he wants to protect him, make love to him, and spend his living days with him. Doesn’t that sound like something most people can relate to, regardless of who one loves?
Perhaps in some way, the “true route” of DMMd suggests that to find “true love,” you find someone who completes you, making a bigger whole of the “you” that you could be.
So, after reading this long-ass post, please reconsider how you see Ren/Aoba. I’d love to see some more fanart of them! :P