Jdrama romances with a serious atmosphere?

Looking for not the common romcom. Something focused heavily on the romance aspect with a serious overtone. I feel as though Chugakusei Nikki was the last Jdrama I watched that had a certain ambience to it that I was completely absorbed by. Not really looking for that kind of plot in particular though. 

I realized this because of your requirements that this is how I like my romantic dramas... what a nice realization- Thank You ^_^

+ Hirugao and if you enjoy it then watch the movie

Aishiteiru to Ittekure 

Boku no Ita Jikan 

Destiny-Like Love 

Fukigen na Kajitsu 

Kamisama Mou Sukoshi Dake 

Kekkon Aite wa Chusen de 

Kimi ga Kokoro ni Sumitsuita 

Love Shuffle

Otto no Chinpo ga Hairanai 

Perfect Crime- I'm hesitant to recommend this one because I didn't enjoy it

Pornographer- it's bl and if you like it then then I recommend the prequel Mood Indigo

Saikou no Rikon 

Utsukushii Hito- the newer Korean remake Love in Sadness isn't bad if you want something more recent

When I think about it, anything with Saito Takumi aka Mr. Steal-Yo-Girl is romantic but has complications

Last Friends 

One Litre of Tears 

Sachiiro no one room 

Koizora 

There's a lot of recommendations already, but I wanna add Tatta Hitotsu no Koi.