Youhei has figured out that in order to stop Riku's transformation into a Kanshu, he needs to give him a Jinki nucleus just like the ones him and Rena have. Youhei asks Takao if he could borrow one of the ones he's obtained, but Takao is insulted by this request. He gets very angry and activates all the Jinki in his possession. Rena attempts to stop Takao's attack, but is injured due to his overwhelming force. Neene then begins to stare off into space, and steps into the line of fire. Takao noticies Rena trying to save her, but before he could attack Youhei stops him. Riku collapses after he has one of those Kanshu related headaches and is exposed to Takao's attacks. Youhei makes an attempt to save him, but is impaled by the multiple Jinki. Takao, thinking he killed them both, advances toward Rena.
But elsewhere, it seems that Youhei suceeded in saving Riku, but at a terrible cost. He laments that their meeting again should not have ended up this way, and that his own Jinki core/nucleus will have to suffice. He explains to Riku that they're the same; When faced with situations where there was no way out, a person appeared to save them. Youhei was entrusted by the person who saved him with the jinki, but because of that the person is no longer around. He apologizes to Riku, but affirms that it's his turn to pass on the weapon - his sensei's legacy -... and his life!
Back to Rena, she is unsuccessful at fending off Takao's attacks and wonders if she can keep it up any longer. Caught off guard, Takao delivers what might be a fatal blow, but is saved by a familliar blade. Thinking it's Youhei, Rena begins to call out his name, but is interrupted by Neene's "Papa!" We then see Riku with an oversized jinki. He tells Takao that he's thought about it, and that he's turning down his offer to leave together with him, and that he's figured out the reason why.

A news-copter hovers over the disaster on the roof of the NEFT building. They spot a familliar figure, Takao, but cannot identify the others...
Back to the duel, it seems Takao is upset with the fact that Riku has become a Jinki wielder. He draws only one Jinki this time. Neene runs over to Riku, and Rena asks where Takabe-san (Youhei) is. Riku assures her "it's alright". Takao takes the opportunity to attack, but Rena reacts fast enough to get them out of danger. She chides Riku for his lack of attention, and warns him that all Jinki have a limit, and she's just about reached hers. Rena then collapses, leaving him to his own devices. With Neene in one hand and Jinki in the other, he attempts to fight back Takao's assaults. Rena analyzes the flaws in his attacks and his cluelessness. She also remembers his lie about it being alright.
Takao asks about Riku's original intention to leave her, and return to "happier days". Catching him off guard, Takao pins him to the wall. Takao declares that he doesn't care about what Riku intends to do, he just wants him and Neene to go along quietly. He shouts his frustrations about Youhei making Riku a Jinki user, and states that now they are both "monsters". Riku remember's Youhei's smile, and tells Takao that despite the fact that he can never go back to those days, he'll cherish those things in his heart - that is what he learned from Youhei.
Breaking out of Takao's grasp, he overwhelms him with the help of Neene. Riku's sudden explosive powers knocks Takao off the building, seperating him from the Jinki cores, and the entire NEFT staff is seen in shock.
Riku has reverted back to his normal self, and Rena asks again about Youhei. We then see a decayed body in what was once Youhei's clothes. Rena loses it, saying that as his partner, it was her responsibility to end his life. Hysterical, she is pulled off of Riku by NEFT staff, who are in disbelief.
Below, we find that Takao survived, and is talking on his phone. He tells about his failure in obtaining the cores, mutters the name "Julie", and jumps into the night.

Riku rings his doorbell and a worried Shizuru greets them. We cut over to breakfast (loli leik toast, lol), and Shizuru wants to discuss Neene and her sudden growth. She scolds Riku for worrying her, but Riku reassures her that he stayed over at an ill friend's house. He subconciously reminds himself that he's still lying, and leaves for school.
The incident 2 nights before is on everyone's mind. The news and people are speculating the cause of this, and many have narrowed down their opinions to Takao, but are reminded about the "white-haired guy" with him.
We find out that it's the end of the term for students, and Riku's classmates invite him over for a celebration. Riku quietly turns them down and walks off alone - his friends noticing the change in mood.
He calls Shizuru at the train station, asking about Neene, and she tells him some startling things. It seems that despite being healthy, the results were a little abnormal, espcially concerning her brain and her ears. She concludes that she can't be human. She then asks Riku who's house he's visiting, and he tells her Takabe Youhei. Shizuru says the name doesn't ring a bell. We are then shown an image in Riku's memory, of Amane, Youhei and himself with a somewhat younger Shizuru. Youhei has already been forgotten.
Riku loses his composure and collapses in the middle of the terminal, crying. We see his last moments with Youhei, who is on the verge of turning into a Kanshu. He tells Riku to remember two things: Kill him before he becomes a Kanshu - Youhei did the same for his teacher -, and the second is to not forget him. We then see Riku execute his friend.
Rena finds Riku sobbing in the terminal, telling him that it isn't the place for such things. She tells him that since he was given this burden to carry, that he ought to know what it was Youhei was fighting for. This reminds Riku about the other hands that pulled him in such a way that he began to walk forward.

The whole aspect of the Kanshu infecting people through the electromagnetic waves of the cellphone is quite a clever device from Moriyama-san.

What I have understood is sort of a parasitic infection which attacks and robs the host of all of his and her memories.

At first, the Kanshu recalled me of Busou Renkin's homunculus. But given that the Kanshu multiply faster their numbers by infecting ordinary people for a taste of flesh it gives me memories for no reason about Claymore's Awakened Beings.

Anyways, I never saw it coming that Riku would drastically transform and his personality starts to spin to a 180 degrees. He looks to me that Nenee, cute baby-girl with dog-like ears, out of instinctive love towards Riku she transformed him into a human-Kanshu hybrid.

But looks like Riku has less than 70 hours before the infection completely corrodes his mind, thus resulting in the total loss of his memories and the end of his ego.

However, someone at NEFT explained that they have found out that actually the human consciousness is not deleted once the infection takes over, rather that it dives into a deep level.

Really, I do not know what I can make about the story, only that it's intriguing and builds loads of adrenaline for suspense.

I have been wondering whether or not Neneé is actually a Kanshu, given her unique physical and DNA make-up, or like Tamao told to Riku that by him properly raising her she'll grow up to become Amane; Riku's deceased sister.

The physical resemblance among the girls is remarkable and what's more surprising is the rate at how fast Neneé is growing-up.

I was little surprise that Youhei(don't if that's how you spell his name) died so quickly I was expecting him to die but not this quickly and that Riku was force to kill him.

"Dad and Mom are not allowed to have quarrels."

Best timing to declare her family construction project. Nene is really genius.