Kimetsu no Yaiba

Since ancient times, rumors have abounded of man-eating demons lurking in the woods. Because of this, the local townsfolk never venture outside at night. Legend has it that a demon slayer also roams the night, hunting down these bloodthirsty demons. For young Tanjirou, these rumors will soon to become his harsh reality...

Ever since the death of his father, Tanjirou has taken it upon himself to support his family. Although their lives may be hardened by tragedy, they've found happiness. But that ephemeral warmth is shattered one day when Tanjirou finds his family slaughtered and the lone survivor, his sister Nezuko, turned into a demon. To his surprise, however, Nezuko still shows signs of human emotion and thought...

Thus begins Tanjirou's quest to fight demons and turn his sister human again.

(Source: VIZ Media)

Volume 7 contains a bonus chapter about Kanao Tsuyuri.
Volume 10 contains a bonus chapter about Inosuke Hashibira.

Kimetsu no Yaiba: Shiawase no Hana

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

1. Shiawase no Hana
Takes place after the Drum House arc and centers around Tanjiro, Zenitsu, and Inosuke bonding while attending a village wedding.
2. 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.
3. 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.
4. Aoi to Kanao
Shinobu sends Kanao to accompany Aoi on a trip to the apothecary.
5. 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.

(Souce: Anilist)

Kimetsu no Yaiba: Shiawase no Hana Franchise