TouhouWiki said: The Ghost Team's ending in Imperishable Night reveals that Eirin herself has consumed the Hourai Elixir (lost in translation, especially due to not being stated directly). The gist of the conversation is that she has taken medicine prepared through Kaguya's power and therefore can never become a resident of the Netherworld.
Arghh~... They're late...It's probably a bad idea taking the curse of death along with us.But it can't be helped if that's the girl's instinctive behavior.You mean to show that video to the princess and master?But leaving that girl in the bamboo forest is...Hey hey.I'm a princess. A princess's order is absolute~....Shouldn't you clean up a little since you have time to spare?I can't~ I'm busy waiting for Tewi and the others.Just a little joke.I am bored. Bring something funny~ Using an old noble dialect.By now, shouldn't it be all right, taking her along with us to Eientei?In the first place, that Tewi, it wasn't anything to take serious about...Did you say something to her?Hey... wait.Eh... Huh? I'm ... a princess...huh? Eirin...?Certainly A PrincessEven if they're immortals, I don't know what will happen...Hmmm... but...Inaba, Behind You. Behind You.Ohohohogudee~Besides, our house has immortals, so won't it be fine?Just kidding~....you sounded just like a princess.Ahh....Sheesh, Kaguya...Ahhhhhhhh!