Nine

Time travel that messed everything up.
After discovering a mystery incense stick, Seol-A finds out that she can travel back in time by lighting the incense stick. With her new ability, Seol-A saves her mother and thinks she's finally found her happy ending. However, she realizes that her time-traveling ability comes with a price when she finds out that her first love I-Jun is now dating her best friend...

(Source: Manta, edited)

Note: This work is inspired by the K-Drama "Nine: Nine Time Travels".