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.
http://rules.l5r.com/EE_The_Player#Player_abilities
(Proclaim) Reaction: After you bring a Personality in your province with your Clan alignment into play without Clan discount, if it is your turn: Gain Honor equal to his base Personal Honor.
If I buy someone FIRST in my turn for honour, and Jiramu is the SECOND person I buy, does his trait still apply and allow me to proclaim him as the 2nd Proclaim?
I presume you're playing Journey's End Keep XP
The trait becomes active as soon as Jiramu enters play, so the timing window for Proclaim ("after you bring XXX into play") is about to open. When you intend to announce the Proclaim Reaction, it checks that you haven't reached the (new) maximum number of uses (2), so it's legal to do.