Ageusia

"My friend had ageusia once. If you don't know this type of disease that I've mentioned, then it's a disease when your taste buds have no use. Oh, and don't try to confuse with anosmia - a loss of the sense of smell. That's because your tongue can only indicate indicate texture and differentiate between sweet, sour, bitter, salty and umami tastes, right? Well, not to mention, the magic of delicious miracles can handle that too."

--Su Ji-Hoon, Ageusiacs

Ageusia is the loss of taste functions of the tongue, particularly the inability to detect sweetness, sourness, bitterness, saltiness, and umami (meaning "pleasant/savory taste"). It is sometimes confused with anosmia – a loss of the sense of smell. Because the tongue can only indicate texture and differentiate between sweet, sour, bitter, salty, and umami, most of what is perceived as the sense of taste is actually derived from smell. True ageusia is relatively rare compared to hypogeusia – a partial loss of taste – and dysgeusia – a distortion or alteration of taste.

In When the Cold Breeze Blows Away, there are mostly happened to other victims who have taste disorders that they can being suffered from it because of each reasonables

Therefore,some medical organizations will know and make medical treatments which solve it. And there are not only have cures and medical treatments,there are include Delicious Miracle and magical cures which can make any cases being cured and no longer suffer from it.