Highly career-focused and tight scheduled Miyuki suddenly finds herself in Istanbul on her 30th birthday, when her house-mates Kyoko and Kaori purchase a ticket for a Mystery Vacation tour as a birthday present for her to relax and explore new places.
She follows the various clues provided in the tour, also exploring the touristic sites of Istanbul, never suspecting that the tour will take her on a journey towards not only new discoveries but also towards her dreams and her distant teenage love in the past.