As Haru walks home from school, she arrives outside of Tsuna's house and sees Tsuna and Lambo's shadows in the window. As Haru watches them, envious of Lambo for getting to play with Tsuna everyday, Haru sees Tsuna seemingly strangling Lambo despite Lambo's protests. However, Tsuna and Lambo are actually playing video games with Lambo happily jumping up and down while I-Pin watches the two. From outside, Haru collapses, unable to believe that Tsuna is a bully. Haru thinks about Tsuna arguing with Reborn and throwing I-Pin around and thinks if he really is the same Tsuna that she first met. As Haru wonders aloud what to do, Bianchi suggests that she test him.
The next day, Haru meets up with Bianchi and Reborn, carrying all the stuff she needs for Tsuna's How is he as a person? test. Haru starts with the first test, Kindness Everyone Knows and plants 100 yen in the street. As Tsuna walks through the streets, he sees the money and goes to buy a drink. Haru is surprised by this but Bianchi and Reborn expected that Tsuna would not go do some troublesome things like going to the police station. Bianchi tells them that she put an address and phone number on the back but Bianchi tells her that it would be hard to read. Haru decides that it's to early to judge Tsuna and starts her next test.
Haru goes make a mask out of silicon to pose as an old lady and asks Tsuna to get him to escort her. As Haru waits for Tsuna, she begins to sweat and causes the mask to melt. Tsuna sees her face and runs for it, screaming. Haru is surprised to see Tsuna's actions but decides to trust him one more time. Haru goes and wears a Namahage costume in order to scare the kids and test if Tsuna is going to save them. Haru goes to the playground but her plan fails since the children are fascinated by her. Tsuna walks by and leaves, thinking that he's seeing a lot of weird things that day. Haru is surprised to see that Tsuna no longer has a human's conscience and tries to go after him. However, she trips just as the police arrive to arrest her for carrying a knife along with Tsuna.
At the police station, Haru and Tsuna are allowed to go with a warning, since the knife was fake. Tsuna asks Haru what she was doing but she ignores him and tries to go home. However, she twisted her ankle during her fall and the police orders Tsuna to carry her home. As the two are passing a bridge, Haru tells Tsuna to let her down but he refuses, saying that she would have to crawl home and that would make him a bad guy. When Haru asks him why does he care since it's his real identity, Tsuna expresses his confusion and asks what she is talking about, causing Haru to shout at his ear and call him a heartless person. Just then, Lambo arrives and asks Tsuna if they are going to play the game again, Haru thinks that game refers to abuse. Lamb sees something hanging out of Haru's bag and pulls it revealing the Namahage costume. Lambo jumps in fright and almost falls to the river. Haru is able to save him with Tsuna pulling her to not fall too. Haru tries to get Tsuna to pull Lambo up but Tsuna is unable to do so since he has no strength. Haru tells him that she would fall instead, causing Tsuna to shout at her, telling her to stop talking non-sense. Reborn, watching from afar, shoots Tsuna with the dying will bullet. Tsuna is able to save Lambo while Haru begins to fall to the river. Tsuna jumps off the bridge too and grabs her and, with a supplementary bullet from Reborn, saves her. However, the two land on the top of a truck and get sent to the police station again...