So, the teaser of third episode has been out and I think it's better to put it here first so we can discuss it! \o/
From the Mikagura School Suite Anime website:
"Eruna, who received an ability named "Toy Gun" from a mysterious girl, got a splendid victory in her first opposition battle. However, when she came to Seisa's mansion to inform this news, Seisa said that her victory is merely comes from Himi's unpreparedness. Eruna who didn't accept Seisa's words then challenged her into a simulation battle, which then accepted by Seisa as the battle will be Eruna's last requirement to be acknowledged as an official member, only if she is able to defeat Seisa."