Kimetsu no Yaiba: The Flower of Happiness

Kimetsu no Yaiba: Flower of Happiness (: しあわせの) is the first light novel series from the Kimetsu no Yaiba (Manga) written by Aya Yajima.

Synopsis
There are five chapters in total, as well as an afterword.

Chapter 1: Flower of Happiness (しあわせの {{Ruby|花|はな}})
Ten days following the events of the Tsuzumi Mansion Arc, the group is seen staying at the Wisteria House belonging to Hisa. While in her care, the group is informed of a wedding which is going to occur, and are invited to give their blessing. Following the wedding, the group overhears two girls speaking of the "Flower of Happiness", which is said to bestow happiness to whoever finds it. Tanjiro becomes intrigued with the rumor, and sets out to find the flower for Nezuko's sake.

Chapter 2: For Whose Sake ({{Ruby|誰|だれ}}が{{Ruby|為|ため}}に)
Following the events of the Natagumo Mountain Arc, the group is now staying at the Butterfly Mansion. At night, Zenitsu takes Nezuko out on a walk to a nearby flower patch, and reminisces on the memories of his training. During one instance, he escaped his lesson and discovered a girl crying in the forest. Upon asking what's wrong, the girl named Sayuri reveals that she has been offered to a nearby Demon by her step-father, as a sacrifice for her family's protection. Outraged, Zenitsu sets off to locate and defeat the Demon in order to protect Sayuri.

Chapter 3: The Chronicles of the Disturbances caused by Fortune Telling ({{Ruby|占|うらな}}い{{Ruby|騒|そう}}{{Ruby|動|どう}}{{Ruby|顛|てん}}{{Ruby|末|まつ}}{{Ruby|記|き}})
After the events of the Mugen Train Arc, the group is travelling back to the Butterfly Mansion after completing a mission. They enter a town buzzing with activity and Zenitsu is called by a fortune teller on the street. The fortune teller tells him that he will have horrible luck with women which will ultimately result in his death. Frightened by the sudden revelation Zenitsu, Inosuke, and Tanjiro must figure out a way to return home while avoiding women, for Zenitsu's sake.

Chapter 4: Aoi and Kanao (アオイとカナヲ)
In the afternoon following her near kidnapping by the Sound Hasira, Aoi is called on by Shinobu to run a few errands. She informs Aoi that she will be sending Kanao to accompany her on her trip as well, leaving Aoi with an uneasy feeling. While at the apothecary, the girls discover they have forgotten their wallets and are forced to figure out a way to collect the items on their list, while bonding to become closer.

Chapter 5: Kimetsu Academy Tales ({{Ruby|中|ちゅう}}{{Ruby|高|こう}}{{Ruby|一|い}}{{Ruby|貫|かん}}☆キメツ{{Ruby|学|がく}}{{Ruby|園|えん}}{{Ruby|物|もの}}{{Ruby|語|かたり}})
Having finally had enough of his duties on the Morals Committee, Zenitsu asks Tanjiro for advice on how to quit. After multiple failed attempts to speak with the gym teacher, Tomioka sensei, the boys seek out the help of the well liked history teacher, Rengoku sensei, to help Zenitsu leave his club.

Afterword
Koyoharu Gotogue relays a story of trying on glasses at a store which ultimately weirded out the employee. They then go on to express their joy at being able to draw illustrations for the novel as well as wish the reader good health and fortune. Aya Yajima expresses her excitement at being able to novelize stories related to Kimetsu no Yaiba and thanks Koyoharu Gotogue for their assistance in the production. Yajima goes on to expresses her gratitude to the members of the publication staff before mentioning her excitement for the anime to air in April.