性格

1. Origins, structure, and basic meaning

• Structure: 性格(せいかく) means the relatively consistent personality or tendencies of a person.
• Basic usage: It describes a cheerful, sociable personality or differences between two people's personalities.

2. Common pitfalls and similar expressions

• Personality and a momentary mood
  • 性格 focuses on a person's lasting tendencies; 気分 focuses on how someone feels at a particular time.
  • 明るい性格 describes a cheerful personality rather than a momentary improvement in mood.