There's a strange disease taking over the world right now.

It's where the infected people start coughing flowers.

For the first few years of its first discovery, it's nothing more but a fairytale for one Honda Hitomi.

Perhaps it's just a joke.

Until her father grieves for her late mother and starts throwing up flowers coated with blood.

Red tulip. Her father throws up red tulips in front of his wife's grave.

—

Her father died two years following that incident.

Red tulip bloomed well inside his lungs.

—

A cure was found for the strange disease. One was to have surgery. This option is limited to those who have yet to show any signs of complications, as they need to remove the plant from the highly fragile tissues inside their lungs. One wrong move could lead to death.

—

Her elder sister, Chaewon, starts coughing Camellia on Hitomi's 19th birthday.

The pink petals of the Camellia remind Hitomi of someone.

Pink hair. 

—

There's a strange scratching inside her chest.

—

Chaewon's coughs starting to get worse. She coughed blood and fainted during her work, leading to her colleague admitting her to the hospital. 

Hitomi sees her pink hair again.