Watashi dake no Koukennin

If nobody wants to support me, I will live on my own! Sarah, an orphan, decides to go on a life journey after cutting ties with her guardian, who she had never seen. As an unmarried, single woman living in nineteenth-century England, she isn't allowed to take a trip by herself. Pretending to be a widow, she stays at a hotel where she runs into her guardian, Marcus Ravenhurst, who happens to be looking for her. With Sarah doing her best to hide her real identity, Marcus protectively observes her and finds himself enchanted with her young innocence…

(Source: Harlequin K.K.)