Demon Slayer: Kimetsu no Yaiba - The Flower of Happiness

The first light novel written by Aya Yajima for Kimetsu no Yaiba containing five chapters, as well as an afterword.

Shiawase no Hana

Takes place after the Drum House arc and centers around Tanjiro, Zenitsu, and Inosuke bonding while attending a village wedding.
Dare ga Tame ni

Takes place after the Natagumo Mountain arc during a "date" between Zenitsu and Nezuko. Zenitsu begins to reminisce about his past encounter with a woman named Sayuri.
Uranai Sōdō Tenmatsuki

Takes place after the Infinity Train arc. Shinobu attempts to cheer the Kamaboko trio up by sending them to buy sweets. On the way back to the Butterfly Mansion, the trio encounter a fortune teller.
Aoi to Kanao

Shinobu sends Kanao to accompany Aoi on a trip to the apothecary.
Chūkōikan ☆ Kimetsu Gakuen Monokatari

Modern-day school alternate universe where Zenitsu has had enough of the Morals Committee and begs his friends to help him quit the club. A seemingly easy task becomes complicated when all of the teachers turn out to be unreliable.