案外

1. Origins, structure, and basic meaning

• Structure: 案外, read あんがい, is an adverb marking a result as unexpectedly different from prior expectations.
• Basic usage: It modifies an apparently difficult task ending early or an old chair proving surprisingly comfortable.

2. Common pitfalls and similar expressions

• An outcome different from expectation
  • It adds a sense of surprise when reality differs from expectation, such as a hard-looking task ending early or an old chair being comfortable. The result is not necessarily positive in every context.