Hana no Namae

Hana no Namae (English: "The Name of the Flower") is a Japanese Shojo Manga by the mangaka Saitou Ken.

The story details the life of Chouko Mizushima, a teenage girl whose parents both die in a car crash. Depressed and refusing to speak, she goes to live with a distant relative, Mizushima Kei, who is a famous post-modern novelist, who has two prestigious awards, whose books have a power to express deep feelings of loneliness and despair. He himself suffers from such feelings and living together Chouko learns to go on and once again becomes a happy girl. But as they become closer, feelings develop and Chouko has to decide whether she wants to brave the kind of loneliness that loving the depressed Kei would bring, And Kei has to decide whether to pull himself out of the dark abyss or risk dragging Chouko down with him.

Tropes used in Hana no Namae include:

Brooding Boy, Gentle Girl: Kei is the brooding boy, Chouko is the gentle girl.
Dark and Troubled Past: Kei he was an illegitimate child, his mother worked herself to death and may have committed suicide, and his family disowned and hated him, and his first girl friend was using him and became sadistic to punish him for being so depressing or something, and then messily broke up with him, nearly destroying him. The guy has reason to be depressed, but he's a dick about it.
Dead Little Sister:
First Guy Wins.
Green Thumb: Chouko. Kei originally told her to garden because she was just wallowing in greif and he wanted to get her out of the way and then she started liking it and came out of her shell.
Heroic BSOD: Both Kei and Chouko at various points.
Hot Springs Episode: Though definitely not filled with your typical fan service.
Japanese School Club: At Chouko's university, she ends up joining a club for reading post-modern literature, everyone there raises up Kei as a God, pretty much.
Kimono Is Traditional: Kei wears Kimonos all the time. He says it's just because the person who willed him the house left them and he didn't feel like buying new clothes.
Last Girl Wins
Most Writers Are Writers: It's a manga (graphic novel), and one of the main characters is a writer.
Not Now, Kiddo: completely averted when it comes to Shinichi and Karasawa
Only Friend: Mizushima Kei's only friend is his editor and biggest fan Akiyama Shinichi, though Kei tries to 'claim' he hates Shinichi.
The Pollyanna: Definitely Chouko.
The Power of Love: Well it is a Shojo Manga.
Stalker with a Crush: Various people can be seen 'stalking' people whom they either love or admire or hate.
The Stoic: Kei.
Stoic Spectacles: Kei, naturally.
They Changed It, Now It Sucks: Expressed in-universe by one of Kei's fans. In his most recent book, Hana, it has an ending that can be very loosely construed as happy (I mean, a little girl dies, it's really not that happy, but the main character is glad to have known her and feels good and stuff). and then writes threatening letters to Kei for 'changing' his style.
The Unfavorite: Kei, in his family.