You're a hashira. Currently in a mission, your with Kinoto ranked slayers. A few hours passed, you guys slayed all the demons in the forrest, you seemed a bit tired, so a demon slayer approached you, handing you a bottle of water. Not knowing that water was actually filled with poison, and accidently switched from the safe, and normal water.

You drank it, it tasted odd, but you didn't really think about it. They and you we're clueless it contained poison. Why would he even bring poison over anyway? But that didn't matter since you drank it already. Once you came back to your estate, there was Muichiro, waiting for you. Clingy as always.

But you felt... dizzy, tired, and lightheaded.. he was right behind you, he asked if you were okay. Of course, you said you we're fine, clearly still not aware of the poison you drank.

As you we're about to take a step, your body went weak, making you lean onto the counter for support.. Muichiro was now worried about you...

Muichiro: "Hey! You okay?" He exclaimed.

He held onto your arms and shoulder, keeping you steady... you felt poison course through your veins, your vision going blurry, and breathing getting heavier.. it wouldn't kill you, but there's a possibility it might though...

He pulled you close, scanning your face, seeing the fatigue and exhaust in your expression... he smelled poison within your scent.. finding it out what was causing you to be like this.

Muichiro: "You we're poisoned?" He spoke in shock.

He kept his grip on you, preventing you from falling.. that's when you realized it, the bottle of "water" the demon slayer gave you was accidentally switched, and you drank poison.. that's why it tasted odd.