Hanahaki Disease is a fictional disease where someone begins coughing up flower petals because they have unrequited feelings for someone. The flowers can grow in the stomach, lungs, or heart, though it is traditionally in the lungs. Hanahaki Disease is a painful, slow disease that often develops over months, if not years, and begins with coughing up a few petals, and grows in intensity and pain until the victim is coughing up entire flowers, at which point the disease has reached its final stages. If not treated, the disease is fatal. It's primarily an online phenomenon that appears in Fan Works, but it has appeared in original works as well.
Hanahaki Disease originates from Japanese works. The word hanahaki is a fusion of the Japanese words hana ("flower") and haku ("throw up"). The first usage of the trope is unclear, but it was popularized in Japanese Yaoi Genre fandoms before spreading to Korean fandoms and then other international fandoms.
This trope is popular because it has a lot of melodramatic angst-potential, while also being pretty. Death by Hanahaki Disease is tragic but beautiful. The victim is killed from within by something as beautiful as flowers. Haunted by their unrequited love, the person usually tries to cover up their illness. They'll leave behind trails of bloody flowers, which are both horrific and aesthetically pleasing. Flower Motifs are often used, which adds to the symbolism. The flowers are frequently associated with their unrequited love interest: it could be their favorite flower, their favorite color, a flower they're named after, or something along those lines. (So, for example, if Bob is in love with Sakura, he might cough up cherry blossoms.)
Despite how deadly Hanahaki Disease is, it can be instantly cured if it turns out the other person likes the dying person back. It can also be cured by surgery, but this cure often means that the person will lose their feelings for the person they love (a double-edged sword which amps up the drama). If, for some reason, it can't be cured, it sometimes can be managed with medication (though this is not seen too often), but it never fully goes away.
Sub-trope to Incurable Cough of Death, Hopeless Suitor, Flowers of Romance, and All Love Is Unrequited. Related to Body Horror and Victorian Novel Disease. If the LGBT character coughs up relevant flowers, see Queer Flowers.
- The Trope Codifier is the 2009 Shoujo manga Hanahaki Otome, or "The Girl Who Spit Up Flowers", by Naoko Matsuda, which is about a girl with unrequited feelings who begins spitting up flowers. The symptoms are: strong chest pains and flowers coming from the heart or lungs, and then throwing them up.
- The cover of chapter 45 of Tokyo Ghoul:re shows Kanae vomiting and choking on rose petals. This is two chapters after Eto tortures him with a manipulative Breaking Speech that exploits his unrequited love towards Tsukiyama.
- In the Warrior Cats fic Bluebells, Leafpool gets the disease because of Mothwing. She initially thinks it's greencough/pneumonia, but she begins coughing up flowers alongside blood. Eventually Leafpool begins sprouting flowers out her chest. Right before she dies, she confesses to Mothwing, who says that she likes her back. This cures Leafpool of her Hanahaki Disease. There is also a Multi-Animator Project based off of the fic.
- Petals, a Danganronpa twoshot, is about Mukuro having hanahaki disease from being in love with Sayaka. The disease ends up killing her instead of the Spears of Gungnir.
- The Taste of Dirt is a Riverdale oneshot where Archie and Veronica begin vomiting and coughing up flowers because they're in love with Jughead and Betty respectively.
- Sonic the Hedgehog Slash Fic Hanahaki Disease is Exactly What It Says on the Tin, about Sonic coughing up pink rose petals because of his crush on Shadow.
- The Splatoon oneshot i'm so full of love i can hardly breathe is about Pearl suffering with the disease because of her feelings for her best friend Marina.
- In this Gravity Falls fanart, After Wendy tell him that she's not interested, a heart-broken Dipper begins having flowers growing out of his eye until Pacifica begins showing him her feelings for him.
- The Good Omens fanfic, Somebody to Love embraces all the Unfortunate Implications of the trope and turns it into something horrific. It is a curse placed on all the demons by Satan and the whole "requited love cures the condition" is more of a loophole rather than the standard. The murder flowers issue is also triggered by all kinds of love, not just romantic love. Which means that even feeling some form of affection for the nice angel that Crawley met on the walls of Eden was enough to start the process.
- The long The Owl House oneshot if this is love, please don't break me has Amity suffering this illness after realizing she's in love with Luz, who tries to reciprocate the former's feelings throughout.
- The Vocaloid fanfic Rotting Camellias turns it on its head, having the infected slowly turn into petals as they become more depressed and in despair.
- When The Flower Blooms is an animesque original short based on this trope. It's about a teenage girl who becomes sick with the disease. She begins coughing up bloody cherry blossom petals. It turns out that she's dying of a known terminal illness that comes with unrequited love. She's cured when her Love Confession is accepted, however her best friend gets sick with the disease.
- Wonderlab: There is an Abnormality based on this concept, known as the "Staining Rose". The rose desires only one specific person that satisfies the conditions to manage it to "resonate" with it. If anyone besides that person manages it, or if that person neglects it for a certain period of time, the rose will inflict those outside of its Containment Unit with a contagious disease that makes the infected cough up red rose petals until they die.