Newlyweds Nana and Shota Tezuka move into an apartment. Two situations, different from the drama series, take place: "What if Shota attends the resident's meeting and not Nana?" and "What if exchange murder game doesn't begin?"

A male corpse is discovered with a smashed face and burned hands. Strangely, the cause of death is determined to be strangulation. When Detective Kaoru Utsumi attempts to corroborate the victim’s ex-wife’s alibi she discovers the mysterious neighbor and only a few small clues to help her disprove a seemingly "airtight" alibi...