Season 3, Part 2, Episode 120: An Invasion from Another Dimension: Mystery of Mugen Academy (EP120)
Résumé de l'épisode 120
Usagi and her friends sneak into Mugen Academy in search of Hotaru, who has gone missing. Meanwhile in the auditorium, Mimete attends the lecture of subspace physicist Sergei Asimov in hopes of outdoing her successor, Tellu.