In a quiet, hidden back alley of Tokyo, a small and historic coffee shop named Funiculi Funicula offers its customers a mind-bending, magical opportunity: the chance to travel back in time. However, the journey comes with strict, absolute rules: you cannot change the present, you can only meet someone who has visited the cafe, and you must return before your cup of coffee gets completely cold. This beautiful, heartwarming novel follows four distinct visitors looking for closure, a final conversation, or a chance to mend a broken relationship. The narrative serves as a deeply moving, bittersweet exploration of regret, love, and the enduring power of human connection.