It’s supposed to be her arc after all. In exchange however, we are introduced to two new and relatively intriguing characters.
The only time we see our resident yandere-imouto is in the OP, which continues to be cutely awesome still.
The episode continues from the last one, with Koyomi on the way to introducing Karen to Kanbaru. A rather weird scene here about rock-paper-scissors, which I don’t really get whether it was random or not. A punishment game had been made out of it and the loser had to carry the winner. Karen “lost” since she cheated so instead of a piggyback she had to carry Koyomi on her shoulders. Because her ponytail was in the way, she cut it off with her house key. Seriously, what’s with this show and girls’ hair.
On the way to Kanbaru’s, the two encounter Kagenui Yodzuru – a mysterious new character that seems to know about oddities as well, calling Koyomi a “devil boy” and Karen a “hornet girl”. She asks for the location of Eikou Cram School. Sure enough, to those who’ve watched Bakemonogatari, the cram school in question was the same one where Oshino stayed. Kagenui leaves, but before that she asks that Koyomi do the same for another girl that was also looking for the school.
The two finally meet. Whether it’s for the better is beyond me.
On his way back, Koyomi spots Hachikuji wandering around. Similar to a scene back in the earlier episodes, Koyomi justifies to us, the viewers (yes, he broke the fourth wall again) his glomping aka sexual harassment of Hachikuji. However, his efforts were in vain thanks to a helping hand from everyone’s favorite loli-vampire.
After a back and forth gag display by Koyomi and Hachikuji, the second girl makes her appearance.
Misaka Imouto Ononoki Yotsugi, the girl mentioned by Kagenui, indeed does ask the location of the cram school. And again, she too may know about oddities as well, calling Hachikuji a “snail girl”
I guess this is more of an “intro” episode for the Tsukihi Phoenix arc. If Kagenui and Ononoki are our enemies is unclear at the moment. For all we know, they might be acquainted with Oshino.