Koushi Sugawara x Sawamura Daichi

Hanahaki disease is a fictional disease where the victim of unrequited or one-sided love begins to vomit or cough up the petals and flowers of a flowering plant growing in their lungs, which will eventually grow large enough to render breathing impossible if left untreated. There is no set flower that blossoms in the lungs but it may be the enamoured's favourite flower or favorite color. It can be cured by the reciprocation of the victim's feelings. These feelings cannot be feelings of friendship but must be feelings of genuine love.