Episode 11, 10 minutes and 46 seconds. Akihito reads the e-mail from Kuriyama-san.
"I'll be on my way to go see you, Senpai. I'll go…and defeat Beyond the Boundry."
While Akihito was reading the mail, Kuriyama-san was fighting with Byond the Boundry.
She pulled the lightning, and then landing in this arbor.