Hikari wants to know what you're doing in there. Actually, she was looking for Yuki who was talking with Takashi-Sensei earlier.
Takahashi-Sensei figured out whether Yuki's Snow Woman powers were dangerous to other people. Yuki just didn't know he was doing that at the time.
Yay! Hikari gets to hug her favorite cold body again. And she went further with getting to nibble her! Nom nom nom nom.
The girls talked with Takahashi about how they address each other. Hikari is Hikari because if she were Hikari-chan, she'd just keep saying "'sup!" all the time.
Unfortunately, no Sakie-Sensei this week. So here she is from the opening credits embarrassed about her sexy succubus nature.