Kazuo Ishiguro’s When We Were Orphans (2000) has been regarded as a hybrid of his previous four novels. Among seven parts, in the first three, set in 1930s London, Christopher Banks, a private detective, recounts his previous life and career, particularly his childhood in Shanghai. Several features in these parts, such as the seemingly realistic settings, the form of memoir, Banks’ poised voice, and the historical details behind his personal life, may remind readers of Ishiguro’s first three novels. However, in the middle parts, Banks’ narrative becomes irrational after he returns to Shanghai in 1937 to rescue his parents. These parts bear some resemblance to Ishiguro’s fourth novel, The Unconsoled (1995). However, the fictional world of When We Were Orphans, which hovers between the seemingly realistic worlds of his first three novels and the dreamlike one of The Unconsoled, has been denounced for lacking coherence. This study, focusing on Ishiguro’s narrative techniques, discusses When We Were Orphans as his challenge to British detective novels and the Bildungsroman, especially written during the Victorian era, by illuminating that some implausible descriptions in the novel are partly based on elements and conventions of these precursory novels rather than on social and cultural norms of London or Shanghai in the early 20th century.