The haibun is the combination of two poems: a prose poem and haiku. The form was popularized by the 17th century Japanese poet Matsuo Basho. Both the prose poem and haiku typically communicate with each other, though poets employ different strategies for this communication—some doing so subtly, while others are more direct.
The prose poem usually describes a scene or moment in an objective manner. In other words, the pronoun “I” isn’t often used—if at all. Meanwhile, the haiku follows the typical rules for haiku. - from WritersDigest.com
A traditional Japanese haiku is a three-line poem with seventeen syllables, written in a 5/7/5 syllable count. Often focusing on images from nature, haiku emphasizes simplicity, intensity, and directness of expression. - from Poets.org