Mimetic interjection representing hearty or open laughter. Often used in casual, friendly, or slightly exaggerated contexts.
"Ha ha ha, that's funny," he laughed.
The manga character laughs loudly, "Ha ha ha."
Katakana spelling is typical for onomatopoeic laughter in manga, games, and casual writing.
Hiragana spelling is also used, especially in more literary or softer contexts.
Onomatopoeic representation of laughter, directly mimicking the sound of laughing.