Shosuro Hirobumi can make that one personality doesn't bow for the battle resolution?
Shosuro Hirobumi and battle resolution
A topic from AEG's L5R CCG Rules forum, copied for Oracle of the Void from a copy of the forum saved in October 2015, so pages it didn't save are missing. Players' names are left out; the rules officials are named. Rulings are as they stood on these dates; later rulings, the rulebooks and the Rules Archive may differ.
Reaction: After your target Personality at Hirobumi's location bows, bow Hirobumi: Straighten the Personality.
Aside: Shosuro Hirobumi's Reaction doesn't negate a bowing effect: it straightens a Personality after she bows.
Shosuro Hirobumi can make that one personality doesn't bow for the battle resolution?
It depends on Shosuro Hirobumi's location during battle resolution. In order to use that ability during the final steps of a battle, the attacking Personality whom you want to straighten must be at the same location as your unbowed Shosuro Hirobumi when she is bowed by battle resolution: at home (see below). If Shosuro Hirobumi was in the same attacking army, then battle resolution bows him simultaneously so his Reaction cannot be taken. If Shosuro Hirobumi is unbowed and at home when all attacking units return home, then his Reaction can be taken to straighten a Personality who is bowed by battle resolution because her bowing happens after she returns home (see below).
Battle, Final steps: "Regardless of who wins, loses, or ties in the battle, all attacking and allied units at its battlefield return home, and these units are then bowed if they returned home."