Demon Slayer: I Became the Water Hashira's Successor, and Now He's Clingy

[BG + Giyu Tomioka pairing + original female protagonist + follows the original storyline + everyone survives + no canon couples broken up]

A hundred years ago, the Fujiwara family was nearly wiped out by Doma, Upper Rank Two. One of the Water Hashira at the time sacrificed himself, holding Doma off until dawn and saving part of the family.

The Fujiwara family never forgot this kindness and continued to help the Demon Slayer Corps.

When Fujiwara Chiyo was fifteen, Giyu Tomioka needed to kill a Lower Rank demon. The demon was good at hiding, so Giyu stayed at the Fujiwara estate for several days to lie in wait.

During that time, Chiyo quietly copied Giyu’s training. She asked him to teach her, and when he saw how quickly she was improving, he trained her for two days.

After completing his mission, he gave Chiyo his own dulled Nichirin Blade.

On the day Chiyo turned nineteen, demons slaughtered the Fujiwara family.

The once-arrogant young heiress bowed her head. She grew up overnight, her personality changed, and she learned to bury her real thoughts and emotions deep inside. She took part in the Demon Slayer Corps entrance selection and passed alongside Tanjiro.

Later, Chiyo went on missions with Tanjiro, Nezuko, Zenitsu, and Inosuke. She carefully crafted the image of “Big Sister Chiyo,” a gentle, dependable girl who always wore a warm smile and looked after the boys in every way. Her disguise was almost perfect, until Tanjiro, with his keen sense of smell, exposed the truth one late night: “Miss Fujiwara, your scent is full of sadness and anger… Why are you always smiling?”