Chapter 159

Short Summary
In response to Nakamura and Karma's teasing, Kayano simply dismisses her chocolate as a formality. Unconvinced, Karma pulls out his phone revealing a picture of her being kissed by Nagisa, which mortifies her. The teasing pair noticed that Kayano had been unable to hide her feelings for Nagisa since that event and figure if they could hook them up, they would have more fun teasing them both. Nevertheless, they are willing to help Kayano decide how to give Nagisa her chocolate by observing other pairs.

After observing a number of couples, including Sugino and Kanzaki, Hayami and Chiba, and finally Kataoka and Isogai, they conclude Kayano simply needed to give Nagisa her chocolate in her own way.

When Kayano meets up with Nagisa, she witnesses the latter attempt to shoot Korosensei, but stops after realizing he was too far. She reminisces on Nagisa's expression when he was about to kill someone, noting that was the reason for her infatuation. As such, she hands him the chocolate out of gratitude for staying by her side. The observing Nakamura and Karma respect her decision to support someone else, and then observe Korosensei looking at a picture of Aguri Yukimura, which Kayano gave to the pair.

Long Summary
In response to Nakamura and Karma's teasing, Kayano simply dismisses her chocolate as a formality. Unconvinced, Karma pulls out his phone revealing a picture of her being kissed by Nagisa, which mortifies her. The teasing pair noticed that Kayano had been unable to hide her feelings for Nagisa since that event and figure if they could hook them up, they would have more fun teasing them both. Nevertheless, they are willing to help Kayano decide how to give Nagisa her chocolate by observing other pairs.

The trio first observe Sugino and Kanzaki, the former repeatedly ramming himself on a pole upon receiving chocolate from Kanzaki. However, since she gave him the chocolates as a formality, the gang look for other couples.

Not long after, they view Hayami handing chocolate chips to Chiba out of respect. Nakamura notes that their relationship was very professional, to which Kayano comments she wouldn't be able to tell if it anything more than platonic. Hazama hands chocolate to Yoshida, Muramatsu, Itona and Terasaka as well as a "love letter". Karma is briefly frustrated, as he had Okuda prepare cyanide-laced chocolate for Terasaka, much to Kayano's horror.

Next, they observe Kataoka hand Isogai a large bag of outlet mall chocolates as a gift to him and his siblings. After the pair stroll off, the gang above concludes that Kayano just needed to hand Nagisa the chocolate in her own way. Karma asks for something from Kayano to aid in an assassination attempt.

As Nagisa prepares to leave class, Kayano pulls him toward her. After asking him about his possible career, she hypothesizes that he wants to be a teacher. Nagisa notices Korosensei on a tree and rushes to kill him, but concludes that he was out of range. Upon seeing that, Kayano is reminded that the expression he makes when honing on his target is what made her infatuated in the first place. As a result, she hands him her chocolate out of gratitude for being by her side, not wanting to get in the way of his future. Nakamura and Karma respect her decision (although Nakamura notes she wouldn't be able to steal Nagisa from her), connecting her desire to support someone else to their former teacher. As they observe Korosensei looking at a photo of said teacher in a bikini (which was the object Kayano offered to the duo), Karma states he would have created a plan to assassinate him if he had known how effective the photo was.