Kagome survived the poison because Inuyasha’s sword protected her; later, the story makes clear that the sword preserved her life and Myōga confirms it. In that scene, she ends up coming out of the poison unharmed, which is treated as unusual even by the characters.

What happened

  • Kagome was exposed to Sesshōmaru’s poison.
  • Instead of dying, she was protected and survived.
  • The explanation given in-universe is that the sword preserved her life.

Simple version

If you were wondering “why didn’t the poison kill Kagome?”, the short answer is: the sword’s power kept her alive.

Quick note

There are also fan discussions online about other poison-related moments in InuYasha, but the clearest canonical explanation for this scene is the sword’s protection.

If you want, I can also explain which episode or chapter this happens in.