How the manga could've gone down with proper communication: Sakai: "Shizuka, you really s...

That's how the conversation would've went down if it took place in some Western country. Two men can't adopt a child in Japan.

Actually, child adoption is very uncommon in Japan for anyone for cultural reasons. Just Google for more info if you're curious.

Just to alter it a bit:

Sakai: "Shizuka, you really seem to like kids... We can't have kids, so are you really okay with being with me?"
Shizuka: "I do like kids, but just being with you is enough for me." *kisses Sakai*
Sakai: "Hehe okay <3"

I know that. I'm sure at least one of them could become a legal guardian. But regardless, the point is the entire situation could've been avoided with 10 second conversation lol

The lack of communication in yaoi manga is so extreme that it's just utterly stupid. It shows poor writing skills / imagination if the author's entire plot-line is based on the fact that a character couldn't say one simple logical sentence.
There are limitless ways to create drama in a plot that isn't based on lack of communication. It's lazy, frustrating, and predictable. /end rant

Think of real life though, so many of the daily disputes and fights are stemmed from simple miscommunication. I agree that there are better plotlines but I still find these realistic.

I get that there are plenty of simple miscommunications and withheld feelings in any relationship. That's normal.
But when you take a simple miscommunication or withheld emotion and blow it out of proportion and create an entire plot out of it,......it's rather ridiculous xD

This guy just saw his lover getting happy over a child:
Decides for himself that his boyfriend would be happier without him, blatantly ignores him, suggests they break up, and then his confused-as-hell lover fell down and lost his memories.

Like.....that's actually insanity >< lol

Another super common over-exaggerated situation in Yaoi manga based on ridiculous assumptions and lack of communication:

Person A sees lover (person B) with another human:

Person A: (Omg who is that? Is he cheating on me? Does he not love me anymore? Is he getting tired of me? Should I break up with him?)
Person B: "I'm home!"
Person A: "Let's break up"
(2 chapters later)
Person B: "That was my sister..."
Person A: "Oh..."

*facepalm*
This is the type of thing I'm talking about. It's not normal couple stuff. It's just plain crazy.

Blowing a tiny thing out of proportion and breaking up over it seems pretty on point from what I've seen people experience. ;)
I get that these kinds aren't your favorite though. I prefer this kind of plot to a love triangle, those are the ones I find super annoying and unrealistic.

Yes! I'll back you up on that one. Totally insane.

Damn....I guess logic is a rare thing xD
But if they break up over something so tiny, the relationship clearly wasn't strong to begin with.

I can't stand love triangles either. It's over-used and also predictable. After reading Yaoi manga for around 10 years, I've become so incredibly nit-picky and constantly looking for something unique. I'm tired of seeing the same plot-lines and themes used over and over again.

Fantasy/supernatural themes are always interesting and they add endless options for plot. But even in regular-life Yaoi manga, drama isn't necessary for a good story. Kokoro by Kanda Neko is my all time favorite. It has no drama, beautiful communication skills, and yet it keeps me entertained and emotionally moved the entire time. That's called good writing and a healthy couple xP

Sadly it is. I majored in Communications and am constantly astonished by people that can't communicate.
In this story, I don't think their relationship was very strong. Because like you said, he broke up too easy. He was already wildly insecure for that tiny thing to set him off. Their feelings were strong, but the relationship was weak. I have hope that their relationship will grow stronger but I don't think it was very strong when the accident happened.
I try not to knock writers because as a writer myself I know how freaking hard it is coming up with a plot.
Kokoro is such a good one! I do like stories where they actually talk to each other.

It's not even just about the kids. He said normal life and family referring to a wife and his parents who would potentially kick him out for being in a gay relationship.