On June 8, 1955, radio message G-3, No.6 proclaimed the activation of the Ateneo de Davao Reserve Officers Training Corps (ROTC) unit. The fledgling unit was then placed under the direct supervision of the Office of the Superintendent ROTC units, HQ IV Military Area (MA), Camp Evangelista, Cagayan de Oro City.

The separation from RMC, however, did not take effect until June 13, 1955. The first commandant was a World War II veteran, Captain Rafael M Sison (FA) PA, with Fr. Manuel Regalado, S.J., Dean of Men, as the first ROTC moderator.

In accordance with ROTC regulations, the unit was provided with training facilities. It was given its own building, which boasted of an office for the commandant, his training staff and cadets, a secure armory for the unit's firearms, and a band room for an 18-man brass band -- this room was later turned into another office for the training staff.

The unit began with only 115 cadets, but with a very high advance ROTC cadet count of six second class, and eleven first class cadets -- all its initial batch of officers were, in fact, advance ROTC course cadets. Despite its youth, and diminutive size, it was to overshadow its older rival ROTC units, Mindanao College (now the University of Mindanao) and the Rizal Memorial College, in its first entry in the Annual Tactical Inspection Competition.

On November 13, 1956, at 2015H, according to college newspaper (Atenews) accounts, radiogram cite RTC 11-25 was received by the Davao Philippine Constabulary (PC) radio station, announcing the AdD-ROTCU as the Number 2 unit in the IV Military Area (all of Mindanao) and the best ROTC unit in Davao City -- the latter being a title it was to hold continuously for almost a decade.

Tactical inspection supremacy was not the sole source of unit prestige. The 50's and 60's saw cadet officers proving their worth both inside and outside the corps. There were corps commanders who were concurrently members of the Student Council, some even becoming presidents. Other officers graduated cum laude. And still others earned reputations as excellent debaters through debate competitions. During AFP sanctioned qualification exams for foreign military training, Ateneans took part; and records indicate that at least one Atenean is known to have topped the exams.

The unit's activities were typical for units of the period. It regularly participated in parades, and on two known occasions was tapped for presidential honor guard duty. Its cadets were burdened by the wait of actual (though firing pinless and non-functional) M1 Garands and M1903 Springfield rifles. Bivouacs were a regular part of its annual activities -- only the Ateneo, UM, and RMC have ever conducted these unique field-training exercises. In 1966, it added the Presentation of Sponsors to its list of ceremonies.

In 1968, it, like all other Davao City-based units, the Ateneo made the gradual, and understandably humorous, transition from English drill instruction to Tagalog commands. The latter became standard by the 1970s.