Rewatching the intro video... and Risa looks pissed that there are new members. She was excited for the "surprise" and then when Momo told it, she barely smiled the entire time during the announcement. When they were setting up the surprise and introducing the girls, she looked like she was warming up to the idea, but she was the only one who didn't look excited.
</blockquote>Risa didn't look happy when she got into CG either. That's just her face.