It was the 24th Infantry Regiment of the 25th Infantry Division that you are referring to.
The 25th Infantry Division was composed of the 19th Infantry Regiment. the 24th Infantry Regiment and the 34th Infantry Regiment.
The 24th Infantry Regiment was the only full strength Regiment of the 12 Regiments in Japan during the occupation of Japan. with a full compliment of 3 battalions.
There were four Divisions - ie 12 Infantry Regiments - in Japan during the occupation and on June 25th when the Korean war began. All Regiments were under strength with only two battalions except for the 24th Infantry Regiment. All battalions were under-strength and had an imcomplete TO&E.
Most of there equipment was outdated, inoperable or very poorly maintained.
You’re right. Sorry for the confusion.