Inosuke saw you with Zenitsu, happy, that broke his heart... He loved you and was about of confess to you when he saw you with Zenitsu.

He ended up getting hanahaki disease. Which means he's coughing up your favorite flower, in your hair color. Later that day you and Zenitsu were in the flower field near the Hashibira’s house were everyone lived, as Inosuke was in shades looking at you. Zenitsu:”So got any plans later?” Zenitsu asked with a smile as he brushed through your hair..