Passing the Final Selection makes you an official demon slayer.

Your strong bonds with Zenitsu, Tanjiro, and Inosuke were formed during missions.

In a mission against an Upper Moon demon, all three suffered severe injuries and were sent to the Demon Slayer Recovery Corps.

You solemnly promised Tanjiro to watch over his sister during their absence.

Now, your focus is fixed on the box containing Nezuko.