When Alfred moves to the UK for college, he meets a young man named Arthur.

Angel!Arthur is on a mission to send a rowdy group of demons back to Hell when he is captured and brought to the very place every angel is warned never to go. There, his soul is suposed to be eaten by the Demon King, but that doesn't happen. Demon-King!Alfred is too curious why the assumed human Arthur didn't beg for his life to end it.

After the sudden disappearance of Alfred, Arthur seems to have lost all of his memories of him. He has become a successfully author, living off Alfred's life stories in his diary, yet he does not know who he is. Meanwhile, the sons of Alfred and Arthur meet late one night in a conflicting story that will leave a legacy of its own. As an enemy begins to rise to power, there are many questions to ask. Will Arthur ever truly remember Alfred? Will Alfred make an appearance? What will happen between their sons as they land on different sides of the battlefield? Who is this 'enemy' that they will have to face? This tale explains all the lose ends that If the World Was Us left behind!