A Tactical Doll, also called T-Doll, is an AI-piloted android originally designed to serve as an easily replaceable fire platform for military operations. Early generation dolls were unmistakably robots, but the standard form of Tactical Dolls came to be that of women as the need for easier human-machine interaction appeared.

After seeing heavy use in World War Three, Tactical Dolls were made available on the civilian market after the war and non-combatant dolls were made commercially available. As of 2062, most T-Dolls are manufactured by I.O.P. and can be found in use by national armies, police forces, PMCs, security companies, civilian companies, and private citizens. Griffin & Kryuger combat forces exclusively employs T-Dolls.

"Tactical Doll" refers specifically to the modern models of dedicated combat androids. Early combat dolls and unarmed civilian dolls are usually called "Autonomous Dolls", privately employed civilian dolls can also be called Domestic Dolls

Taken from: https://iopwiki.com/wiki/Tactical_Doll

Griffin and Kryuger Private Military Company and Security Consultant Company is a paramilitary company founded in 2053 by former special forces soldier Berezovich Kryuger.

G&K is known for mostly employing I.O.P. Tactical Dolls and has been an important sponsor of IOP and 16LAB, directly influencing several design decisions in their T-Dolls standards. By Kryuger's preferences, all Griffin T-Dolls are designated by the weapon they use in combat.

In the Game "Girls' Frontline" you play a Commander Working for G&K.

Taken from: https://iopwiki.com/wiki/Griffin_%26_Kryuger

Important Operations Prototype Manufacturing Company, or IOP, is a R&D and manufacturing company specializing in Tactical Dolls, directed by Havier Witkin. IOP is the world leader in Tactical Doll production since World War Three thanks to 16LAB's groundbreaking technological research, and the main supplier of workforce for Griffin & Kryuger PMC.

Taken from https://iopwiki.com/wiki/I.O.P.

Sangvis Ferri Manufacturing was a weapon manufacturer based in Eastern Europe, created in 2031. They were a major Tactical Doll  manufacturer and researcher under the lead of AI scientist Lycoris before the 2061 Butterfly Incident, when Sangvis Ferri's headquarters were destroyed and their main AI Elisa took control of their T-Dolls and turned against mankind. From then on, Sangvis Ferri was no more the name of a renown military manufacturer, but of a threat to humanity the PMC Griffin & Kryuger was tasked with destroying. As such, they were the first antagonist in Girls' Frontline.

Taken from: https://iopwiki.com/wiki/Sangvis_Ferri

The Butterfly Incident took place in late 2061 in the main labs of Sangvis Ferri as a result of the failure of Operation Butterfly.

Operation Butterfly was led by Tactical Doll under the command of the Sixth Directorate of the Soviet Bureau of State Security. T-Doll M16A1 and HK416 participated in the operation, as well as UMP 40 and UMP 45 as tech support. However, UMP40 was an agent of a third party and the mission failed catastrophically due to her intervention. However, she carried the operation only to protect UMP45 and allow her to break free of human control, and 45 escaped after mercy-killing 40. HK416 and M16A1 also survived.

Top AI scientist professor Lycoris was killed during the operation, provoking the rebellion of Sangvis Ferri's central AI Elisa, who used the Sangvis T-Dolls as her personal army against humanity, starting more than a year of conflict with Griffin & Kryuger, the PMC employed to eliminate them.

Taken from: https://iopwiki.com/wiki/Butterfly_Incident