The title speaks for itself, "Will you marry me again if you are reborn?" The story is about Ibuki and his wife Kaoru who have been devotedly in love ever since they could remember. They are now grandparents. Ibuki is bedridden in a hospital and recalls their past together along with the people around them. The manga is pretty sad and realistic so do have some tissues with you when reading this. It shows how their relationship developed and how the experiences they and their friends and family went through. I believe the title is basically Ibuki asking his wife, "Will you marry me againif you are reborn?" because they both love each other dearly and he is soon to leave the world.