Episode 12 of Hyakko starts with Torako trying to call her friends one night and failing. The next day, it turns out that Torako had been trying to find a friend for a place to stay. Unable to connect to Suzume, Ayumi, or Tatsuki, she ended up staying with Ushio, although they stayed up all night playing games out of the fierce competitiveness between them. Torako had run away from home for the first time after starting high school, which used to be a regular occurrence as Suzume knows all too well, having often accompanied Torako on her escapades.
As Nene is figuratively green with envy that Torako and Ushio spent the night together, Torako’s older sister, Kageyama Oniyuri, appears and wants to know where Torako was. It seems that Oniyuri might be the only other person besides Kitsune that Torako could turn timid against. Suzume obviously knows who Oniyuri is, but everyone is surprised that Nene knows she is, too. It turns out that Oniyuri is the school president, so Nene would have known who she was as class representative, and Nene also suspected that Oniyuri was Torako’s older sister since they had the same surname. Everyone else is surprised at Torako having yet another sibling. The encounter with Oniyuri leaves Torako sad all day long.
When school ends, Oniyuri is ready to drag Torako home. However, Torako refuses to go home as everyone is watching, and the tussle eventually ends with Oniyuri slapping Torako for saying that their parents weren’t her parents. This has Torako running away and getting everyone worried about her. Kitsune summons Ayumi and Tatsuki to talk about Torako’s past, while Suzume is very cutely expressing her extreme displeasure with Oniyuri.
We learn that Torako is a half-sister of Oniyuri and Kitsune. She was born between the father and another woman and moved in with the rest of the family when her mother died. While Torako hardly gets along with her parents and runs away from home whenever there’s a fight, she really likes her siblings and vice versa, even if they’re really bad at showing it. Oniyuri might seem cold and strict, but she really worries about Torako. And even though Kitsune enjoys tormenting Torako way too much, it’s more like him not outgrowing a “torment the person you like” phase. The bond between the three siblings is pretty clearly shown in a flashback to when Kitsune and Torako worked together to avenge their older sister and how Oniyuri handled her younger siblings doing something wrong.
Eventually Torako is ready to leave school, and Oniyuri is waiting to apologize to Torako for slapping her. Torako and Oniyuri are reconciled as Torako sobbingly apologizes in response to Oniyuri’s apology. And as the two sisters start for home, accompanied by Touma who had stayed with Torako on the roof, the rest of Torako’s friends are waiting for her to cheer her up. Oniyuri sends Torako off with her friends and watches happily as her younger sister cheerfully walks among so many of her new friends.
While not devoid of comedy, this episode focused so much more on Torako’s relationship with her siblings and was an interesting way to end the series. Except this isn’t quite the end, and episode 13 was broadcast immediately after this one, which returns Hyakko to the very beginning on the first day of school.