I really want to read something that gets my heart pumping for the characters, aching when their in pain, enthusiastic when they are. Something that just drags you in emotionally to the point that you have no idea why you're crying, you just are. It could be sad, happy, action-y, I don't really care, I just really want something with a lot of emotional depth.

Tadayoedo Shizumazu, Saredo Naki mo Sezu and its sequels
Zankoku na Kami ga Shihai Suru

Hana Wa Saku ka but it's still on-going.

It's the Art of Time, it's the Art of Life--
Of the player and the craftsman,
Of the writer of songs, of the creator of love,
Of those who will follow, of those who led,
There's no other way in the world ahead ♥

I love those kinda manga. And usually they should be long enough to make me attached to the story and characters. These are some that got me.

Totally Captivated, it's long, that's probably why I got so so into the story. I love the story and characters. It's captivating 😀
And near the end it gets so dramatic, you just can't let it go. Some people are like the ending ruined it, but in my idea, the ending was the best.
The Cornered Mouse Dreams of Cheese and its sequel, another great story with great characters. At times it's so frustrating you just wanna kill the character.
New York New York, Ok this would be my number one suggestion for "emotionally draining manga". It's AMAZING! Like....yeah....you know it.
Jazz, again the drama, you just can't let it go and sympathize with the characters.
Cut, I dunno if this is exactly what you're looking for but either way it's an amazing read. Like masterpiece levels. The psychological aspects of it is just great.
Corsair, this one is so underrated, it's crazy. You should read it. It's such a good manga. The character's past just draws you more into the characters. I love it.

PS. All these suggestions have somewhat of a sad part. That's the part that draws me in and makes me more attached to the characters. I dunno if that's the same case for you though.

Enjoy ^.^

[img]https://31.media.tumblr.com/fed8f641faa089fa16ee883f5b18f006/tumblr_n09tpwWCYW1qk16e0o1_500.png[/img]
K n e e l .... This is the difference between your and my eye-level.
Rai from Noblesse

sakura gari
😉

Just to make sure are you looking for just yaoi? or just yuri? or both?

(I'll edit base on response)

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Zetsuai and its sequel Bronze
Super drama content
A lot of emotional stuff

Quote from Kitty18dnsz

Just to make sure are you looking for just yaoi? or just yuri? or both?

(I'll edit base on response)

Either, or, both, I really like to read everything regardless of the sexuality presented XD I just love a good read<3

Quote from mybackhurtz

Tadayoedo Shizumazu, Saredo Naki mo Sezu and its sequels
Zankoku na Kami ga Shihai Suru

I've read Tadayoedo Shizumazu, Saredo Naki mo Sezu, it's really good! I'll definitely check out Zankoku na Kami ga Shihai Suru! Thank you very much for the rec<3

Quote from MirayAllen

Hana Wa Saku ka but it's still on-going.

And if only it would update ;A; that series gives me so many feels

Quote from AngelCharms

I love those kinda manga. And usually they should be long enough to make me attached to the story and characters. These are some that got me.

Totally Captivated, it's long, that's probably why I got so so into the story. I love the story and characters. It's captivating 😀
And near the end it get ...

My gosh, you've recommended some of my absolute favorites along with some I haven't seen before<3 this is definitely promising!!

(Cut makes me cry no matter how many times I re-read it and omfg Totally Captivated is amazing and I totally loved the ending too<3<3 Corsiair is totally underrated, Imma go re-read it because it's awesome<3)

Quote from metrepersecond

sakura gari
😉

Oooooh, I haven't read this one! Thank you very much for the rec! <3

I second Zetsuai and its sequel Bronze. The most dramatic and emotional series I know.

Now my suggestions:
Acid Town
Ai wa Doko Itta?
Dear Green: Hitomi no Ounowa
Let Dai
Love Mode
Nemureru Tsuki
Sorenari ni Shinken nandesu.
Tsumasaki ni Kiss
Under Grand Hotel
Uso to Kiss
Yuuutsu na Asa
ZE

Pieta - Aaaangst
Octave - Really takes a toll on the reader as far as patience with the mc and all the emotional turmoil
A Lollipop or a Bullet - Not either yaoi or yuri, but still has a relationship between two girls within a disturbing story