Love Me Until Death

16 year old Alice made a vow to her bestfriend Keichi that when she grows up she'll be someone worthy of being Keichi's wife, and that Keichi would wait for him on that time to come, however met with circumstances Alice was placed in a coma due to an accident in which she got hit by a car.

As soon as Alice recovered from her deep sleep, she was long forgotten and everyone who knows her thinks that she has ascended into heaven. Will Alice find out what happened to her and be reunited with Keichi and get married?