Uro seems to conclude that Yuta is connected to the Fujiwara line during their fight, based on his demeanor, his comments, and the way he fights rather than any explicit “reveal” scene. The strongest read is that she recognizes something about his heritage or presence that reminds her of the Fujiwara clan, then calls him a Fujiwara in anger.

What’s implied

  • Uro was a former assassin tied to the Fujiwara Clan, so she has a strong historical grudge against them.
  • During the battle, she notices something familiar about Yuta and reacts as if he belongs to that bloodline.
  • Fans have long interpreted this as Uro recognizing Yuta through his lineage, not through a formal confirmation from another character.

Most likely explanation

The manga does not give a clean, step-by-step explanation that Uro “investigated” Yuta and learned the truth off-screen. Instead, the scene reads like a mix of intuition, battlefield recognition, and personal hatred toward the Fujiwara name.

In short

She doesn’t appear to find out through a direct disclosure; she infers it in the middle of combat and lashes out at him as “Fujiwara.”

If you want, I can also break down the exact chapter scene and what Uro says line by line.