Anime: Demon Slayer (Kimetsu No Yaiba)

~~~~~

Main character{s}:

Name: Ecko
Age: 13 (beginning) 15 (when the exam starts) (oldest)
Gender: Female (straight)

Name: Etzel
Age: 11 (beginning) 13 (when the exam starts)  (Middle)
Gender: Male (bi)

Name: Emil
Age: 6 (beginning) 8 (when the exam starts) (youngest)
Gender: Male (gay)

~~~~~

Main plot: Ecko was fit, Etzel was ill, and Emil was oblivious. But a tragedy pushes them from their home to meet a burgundy haired boy her hopes to become a demon slayer, and to Ecko, it wasn't a bad hope...