Dragon Savior

Not even a year into high school, Poli Na has already had enough. Everything seems so pointless, and her own life is no exception. That is, until a mysterious, transparent dragon appears and destroys the planet in a fit of rage. As the only person who can see this crystal-clear dragon, Poli is chosen to travel back in time to another world so that she can save Earth and this alternate world from being destroyed. The fate of two worlds hangs on Poli's efforts to win over Israhi, the invisible dragon, and turn him toward the light.

(Source: Webtoon Entertainment)