Futago no Imouto ni Korosareta Ane, Nidome no Jinsei wa Hatsukoi no Ike Ouji Outei ni Full Bet Shimasu!

Killed by her twin sister, Diana finds herself traveling back in time to the morning of her graduation. She begins her struggle to save Alan, her first love who died in her previous life. A restart for a young lady who met a tragic end—a romance fantasy with a significant age gap begins.