It's a fantasy manga set in Japan during the Edo period. The main character is a chef(?) And his father passed down a possessed kitchen knife. His childhood friend is cursed, and if I recall correctly he has to kill and feed her a giant flying goldfish. I believe chapter 1 has him killing a giant octopus. There's also an office where they have to kill and cook these giant sea animals for jobs.
I don't remember too much since I read it probably in 2020 or some time around then.