She is first seen after the parking lot altercation during Beautiful Agent, gathering up the Black Delmo and the Black Delmo Leader alongside other Blue Delmo.

After this we see her being knocked out on a couple different occasions. The first one is by Maypia Alexymetalia, while she is on guard duty together with Blue Delmo D. On this case, Maypia unceremoniously dispatches the girl by kicking an airshaft grid on her head. Catherine thus plummets loudly to the floor, where she lands unconscious flat on her chest. In this way, Maypia also uses the defeated girl as a decoy to get the other unsuspecting Blue Delmo D to carelessly approach the spot, looking to aid her friend. Just as the remaining soldier begins to realize what's actually happening and turns to face the attackers, Maypia leaves her out of commission with a brutal kick in the face which sends her crashing to the floor, face up and legs wide spread, skirt hiked up above the hips.

The second time is when Rudolf Hagen instructs Catherine to escort Rion Aida to her cell. This time, the soldier is able to almost fulfill her task successfully, taking the prisoner to the door and getting her to enter without problems, even taking the liberty to berate her on the way there. However, things quicky take a turn for the worse as Catherine follows the handcuffed Rion inside the cell. It's unclear how it actually happens, but somehow the untrained teenager seems to be able to gain the upper hand on the supposedly experienced soldier and hastily reduce her. From outside the room, we can only hear a quick succession of blows as the poor girl screams in anguish. Next thing we know, Catherine has been mercilessly subdued, and is lying on the floor unconscious and half naked