Light novel

A light novel (ライトノベル, raito noberu^?) is a style of Japanese novel primarily, but not exclusively, targeting middle- and high-school students (young adult demographic). "Light novel" is a wasei-eigo, or a Japanese term formed from words in the English language. Such short, light novels are often called ranobe (ラノベ^?) or LN in the West. They are typically not more than 40,000–50,000 words long (the shorter ones being equivalent to a novella in Western publishing terms), are rarely more than a few hundred pages, often have dense publishing schedules, are usually published in bunkobon size (A6, 10.5 cm × 14.8 cm), and are often illustrated, mostly with manga style art. The text is often serialized in anthology magazines before collection in book form.

Light novels are an evolution of pulp magazines. To please their audience, in the 1970s, most of the Japanese pulp magazines, which had already changed from the classic style to the popular anime style covers, began to put illustrations in the beginning of each story and included articles about popular anime, movies, and video games. The narrative evolved to please the new generations and became fully illustrated with the popular style. The popular serials are printed in novels.

...
Wikipedia