So Ayari does indeed know about Mariya's secret, as she's his cousin, after all.
The perverse mischievousness of Mariya's grandmother knows no bounds, as both he and Shizu were already crossdressing so so many years.
Kanako is now in full hentai mode, having mistaken a Virgin Mary festival for some opportunity to see hot girls in cosplay. Besides Matsurika having to whack her with a basketball, even Yuzuru had to smack her to protect Sachi from her claws.
(Yuzuru probably wants to keep Sachi for herself, and is thus acting instinctively. )
Sachi gets the completely wrong idea on Kanako's tendency to giggle and lose blood, and thinks she's a delicate person who goes into deep thought a lot. (Come to think of it, I do that a lot as well. xD )
Speaking of hot girls, Ayari's deputy in the student council, Natsuru, sure is gorgeous.
Yonakuni once again is up to no good, releasing the evil hidden in that cursed room. Though it'll probably be resolved within the first 5 minutes of next episode. This might explain the "Part One" subtitle in this episode's title, despite it having absolutely nothing to do with what happened... again.
A slightly different ED animation, and as usual, another WTF "preview". All I can think of with this "preview" is
Billy Herrington, the Nico Meme.
PS I know Kanako's tall, but seeing her stand beside even a senior like Ayari, I realized why Matsurika describes her as the Tokyo Tower.