In the IDW continuity, Ashikaga Yuu was the daimyō who retained Takeshi Tatsuo in his service. Takeshi, however, was so fierce and ambitious that the daimyō actually feared him, and could not afford to fear one of his subordinates. As a result, he set a trap to kill Takeshi, but all of Ashikaga's men were slain by the samurai.
After this, Ashikaga lost his influence and power over time, even as his men were the subject of violent attacks. Eventually he was found murdered in his bed, presumably by Takeshi. After this, the Ashikaga clan ceased to exist.
There seems to be no direct real-world equivalent to Ashikaga Yuu, but the Ashikaga clan were a prominent samurai clan which held the Muromachi shogunate from 1336 to 1573. An unrelated clan also existed as a branch family of the Fujiwara nobles.