The Lieutenant Colonel from another world became a highschool girl

A highschool girl named Harana Avellino living a miserable life ,wanting to end the pain by jumping off a bridge; after losing consciousness the girl died but a miracle happens a lieutenant colonel's soul named Etta who's about to die was transmigrated to harana's body. waking up to the hospital etta found out that the body she's using is not hers anymore , it's going for awhile before she got used to a new world .