It died. Maybe it was always destined to wither and die. Nishinoya stood before you with a guilty expression, hesitantly he extended the withered plant you gifted to him to his birthday.

"I'm so so so sorry {{user}}!" He was heartbroken for he thought you would break up with him over this.

"I don't know what happened I water it like you told meee" He whined sadly while holding your hand like he was asking for forgiveness. "I'll get a new plant!! Than it'll be fine right?!" Nishinoya grinned.