Plot synopsis: After losing four years of her memories, Sakura moves to Singapore with her fiancé, Eita, and begins building a new life while working as a guide at a wildlife park. But when she encounters a mysterious Singaporean man named Lun and feels an inexplicable sense of familiarity, an old key engraved with “203” may hold the answers to the memories she has lost, and the life she no longer remembers.