Sergei Lou (セルゲイ・ロウ), also known as Sergei the Apprehender (搦め手のセルゲイ), is the chief of the Special Support Section.
He earned his title of Sergei the Apprehender as a top-notch investigator with the Crossbell Police Department, where he also supervised Guy Bannings and Arios MacLaine. Under his lead, the First Division's accomplishments exceeded far of what was expected of them.
Zero and Ao no Kiseki
As the acting Section Chief of the SSS, Sergei directed the group to hot-button issues in Crossbell that they needed to resolve and acted as their representative in the Crossbell Police Department. Sergei stressed that the SSS needed to come to decisions independently and to rely on their own judgment as a group in order to make sound decisions in the field and to take quick, effective action.
If the situations calls for it, Sergei quickly dismisses his laid back attitude and immediately takes the initiative. When Joachim Guenter manipulated the Crossbell Guardian Force into attacking Crossbell using Gnosis, Sergei readied his shotgun to hold off the brainwashed forces so that the SSS could escape together with KeA.
After aiding the SSS in their escape, Sergei offered to drive the group to the Sun Fort at the Ancient Battlefield where Joachim was waiting. While attempting to evade the hail of gunfire firing towards the car, he told the SSS that he considered it his duty to clear the path for youngsters like them.
Trails of Cold Steel I, II, III, and IV
During the Imperial occupation of Crossbell, Sergei collaborated with the resistance in the form of transporting relief supplies.
Sergei once again joins the resistance efforts against Rufus Albareas's occupation on the day of their re-independence. After losing a confrontation within the city itself, he retreats to Mainz with other members of the CGF and police. He joined in several operations against the Special Guard including distracting their forces away from the Moon Temple and the final assault on the city itself.
During the assault on Reverse Babel, Sergei leads a boat full of police officers to engage the automated Zauber Soldats upon the Lake.