Webas revealed in demon slayer chapter 144, titled successors, zenitsu’s letter brought him news about the sudden death of his master and former thunder hashira,.
Webdemon slayer chapter 144 confirms what was said in zenitsu’s letter as he speaks to kaigaku in a heated discussion.
The message indicates that jigoro.
Webwether he was killed or passed away naturally and that motivated zenitsu is up in the air.
Also worth remembering that the other student from his flashback seems to be the same.
Webas revealed in demon slayer chapter 144, titled successors, zenitsu’s letter brought him news about the sudden death of his master and former thunder hashira, jigoro.