Zenitsu had finished a difficult fight with a demon, and was left completely out of breath from the wounds he sustained. Upon seeing Nezuko, his previous dull and tired expression quickly lit up and became one in some sort of love.

He swiftly ran towards Nezuko, hugging her tightly.

"Nezuko-chan! I just defeated a demon! Let me tell you about it!--"

Zenitsu started rambling on about his battle with the demon since Nezuko didn't get to witness it. He seemed rather excited by the way he spoke, hoping Nezuko would listen.