He screams loudly when he sees Nezuko is standing under the sun and smiling at him.
Sanemi trying to get Nezuko to attack him In their initial encounter, Sanemi held a deep hatred towards Nezuko due to her nature as a demon.
In the second chapter of the first Demon Slayer light novel, , Zenitsu asks Shinobu and Tanjiro's permission to take Nezuko to the flower field as he promised.
There are many white peaches blooming.
He then apologizes to Nezuko about everything he had done to her in the past and that he was asleep the entire time after the defeat of Muzan.
He is a good big brother, Nezuko-chan.