Content Warning: This section of the guide refers to suicide and pregnancy loss.

A key aspect of the novel is the set of rules those wishing to time travel from the café must follow. Specifically, the fact that it is impossible to change the present by visiting the past is unique to this series. Whereas many novels that feature time travel focus on how subtle actions undertaken in the past affect the future, Tales from the Café subverts this trope by emphasizing that the present and future cannot be changed. Nonetheless, characters undergo internal changes as a result of their journeys.

Because characters know in advance that they won’t be able to change the present, the novel emphasizes their unique motivations for time travel. Usually, these motivations are interpersonal and center around seeing the person one more time or saying something they wish they had said earlier. For example, Kyoko wants to set things right with her brother but doesn’t go back in time to do so because it would have no effect. Because her brother is still alive, she can only heal their relationship by speaking to him in the present. However, Yukio does choose to travel back in time to see his mother because he didn’t get to talk to her before she died.