It's the anniversary of Eri's and Kogoro's first date and Ran decided to visit her mother to celebrate the big news! It turns out that her mom is in a rush and seems to be hiding something from Ran and Conan. It looks like her mom is cheating on Ran's dad! How will Ran take this seeing a bunch of solid evidence? Out of deductive reasoning skills, Conan figured out this whole thing could be a HUGE misunderstanding!!