Uranus ♅ Troposphere ♅ Stratosphere
Thermosphere ♅ Exosphere ♅ Outer Space

120 "Invasion from an Alternate Dimension! The Mystery of Mugen Academy"

When Chibiusa rushes to find Hotaru and discovers her house empty in this episode she took her anger out on Setsuna. Setsuna had followed her, worried. When Chibiusa saw her, the woman had a sad, remorseful look upon her face. Chibiusa demands to know where Setsuna took her, when Setsuna had done nothing to Hotaru. When Setsuna explained the house was empty when she got there, Chibiusa accuses her of lying and blames her for Hotaru's leaving.

All of those words from the little girl she loves and is friends with had to have hurt, but she understood and tried to comfort Chibiusa instead. Chibiusa tells her she hates her, but Setsuna hugs her. Those words certainly had to have hurt Setsuna, but she knew in her heart Chibiusa didn't truly mean them. Still to hear them… it had to have been like a knife constantly stabbing her heart.

Later when she brings Chibiusa back home, Mamoru thanks her. Her gaze softens with gratitude of such appraisal. It has been shown in the manga more than the anime that Setsuna greatly admires the royal family of the future. To go against them due to her duty in the past also must have been a strain on her emotions.

When asked to give more information to them on Mugen Gakuen, Setsuna warily concedes. Upon hearing Hotaru possibly being part of the Death Busters and yet such information isn't certain Chibiusa again goes to her defense, directing it at Setsuna with anger. Setsuna's expression falls and her sorrow is evident.

Usagi asks Setsuna if there is a way to get around killing Hotaru. Again she uses the fact that Hotaru is Sailor Saturn, thus a Sailor Soldier like them as her excuse. Setsuna pauses a moment and closes her eyes. They waver some and then she looks at Usagi almost coldly, telling her, "This is why we didn't want to involve you in this battle…"

Moon's team simply couldn't handle anything beyond idealistic.