Hanako Hakase/History

Chapter 1
Hanako drives Buster's van to the location where a new Sagako has appeared for the Busters to contain and seal it.

After Yuko turns into an onion, she is responsible for giving Eikichi the full context of what happened to her sister. Introducing herself and the other members of the group, she is responsible for giving Eikichi the introduction to each girl in Sagako Busters. She describes herself as a beautiful and intelligent woman willing to do anything to save Saga.

When Tae and Eikichi have a problem with the hot spring Sagako, she, along with Anna, brings them onions from the Hyodo farm for Eikichi to try to seal the Sagako.

Chapter 2
Hanako has modified a machine to “make” people more intelligent so that it measures Eikichi's Misogi power and thus has an idea of how his power is increasing little by little. Although it appears that the machine she designed doesn't seem to work with Eikichi.

She later talks to Tae about her attitude towards Eikichi and tells him that he is not like her sister, Yuko, and that they are both entirely different.

Chapter 3
The Busters deal with the case of a Sagako in Saga's club. Upon arrival, they are attacked with cursed music that affects the women and makes them go crazy.

Arriving back at the mansion, Tae tells them that the Sagako was looking for a “triple A” man and, therefore, they should look for one. Or make one. Thanks to her help and her invention, the “Del Height”, she manages to make Eikichi increase his height by 20 centimeters and makes him much more flexible than he already was.

Thanks to her invention that made Eikichi more flexible and taller, he manages to contain and seal the Sagako in the onion drinks he had previously prepared.

Chapter 5
Hanako gets drunk at the Busters' party. She is glad that Tae and MJ have made up when they previously talked on TV. Hanako also reveals Tae's age, which makes her nervous to remind her that she is 29 years old and still hasn't found someone to be with.

After the party, Eikichi takes her back to the mansion. When Eikichi wakes up, Hanako is on him, and she takes the opportunity to use him as her guinea pig by injecting him with a “love potion” that she herself prepared. Earlier at the party, she noticed that Eikichi got nervous when Tae said that she was already in a relationship and made the love potion for Eikichi.

In the morning, she wakes up again after a hangover and receives a fax from a Sagako that appeared at Minami school.

Chapter 6
After the incident with Takeo, he tells them about all the supernatural events at school related to declarations of love. So, she, along with the rest of the team, will not let the curse continue to affect Tae and the school.

After planning a trap with Tae dressed as a schoolgirl, she exclaims how cute the Sagako they're chasing is. Thanks to the love potion that she had created earlier, they trap Sagako… making him fall in love with Eikichi.

Chapter 7
Anna has disappeared from the group, and while the Busters mention how weird Anna is even to them. Before Anna, there were several members who did not exceed 3 days and Hanako tells them that they were useless against the fights against Sagako and, therefore, they did not help them at all. She also says that it was due to Tae's attitude against the new members, to which Tae replies that it's also Hanako's fault for her human experiments.

The next day, Hanako has a discussion with Tae about how to defeat a Hanako that appeared on a beach. She thinks they can defeat it with salt, but without Anna around to take samples, this is nothing more than a guess; she angers Tae for not being able to figure it out before the Sagako ran away.

In the past, there were similar problems. One day, the girls fought over how to defeat a Sagako that was embedded in a wall. Hanako planned to tear down the wall, while Tae told her that this was very extreme of her parts. Neither of them could agree until Anna came up with a solution they hadn't seen before.

Chapter 8
After the previous day's failure, she is reprimanded along with Tae and Eikichi by Jofuku about not being able to combat the Sagako, much less defeat it. She believes that Anna left the group for financial reasons, but Eikichi tells them that they may be assuming too much about Anna's situation, so he goes to look for her himself.

After several hours, Tae and Hanako fight the Goby Eel Sagako, but neither of them has managed to weaken it and their heads are still grown. Finally, Anna is reunited with the group and defeats the Sagako that she and Tae were fighting earlier.

Chapter 9
Anna gives them more details about Higashino and warns them that he is now planning something against Sagako. So, to prevent him from doing more damage, the Busters split up to find him.

Chapter 10
Eikichi was beaten by Higashino when he confronted him about the Sagako he had killed, which left him in a depressed state. Without his help on the team, Hanako, along with the other Busters, cannot fight Sagako directly. MJ warns them that a Sagako outbreak has appeared and that they must attend to.

Upon arrival, they are surprised to see a crowd of Sagako of the same type. Without Eikichi to seal them, they decide to take all the Sagako in the van to the mansion to be sealed afterward when Eikichi recovers. Hanako is responsible for driving (as always) with the load of Sagakos in the van.

With the Sagako locked in a room in the mansion, Hanako worries about Eikichi's current state. Aware that her sitting and waiting will do nothing, she plans to build a device that can contain the Sagako and will also do more research on onions.

Chapter 11
While in the mansion, sheltering from the storm, she mentions that she finds it weird that there was a storm even though the weather forecast said otherwise that morning. Unexpectedly, a loud crash followed by the mansion collapsing causes her and the Busters to quickly seek cover. After the dust clears, she catches a glimpse of a gigantic spider-like creature heading straight for the city. The gigantic creature makes Hanako wonder if it is a Sagako or something else.

Chapter 12
After Tae's battle with the Sagako, she is badly injured and is attended by Anna, who tells her that they should go to the hospital. Hanako reminds them that they don't have health insurance and that they are also homeless and penniless. With nowhere to go, the group accompanies Eikichi to his house, where his family takes the injured group in and fed them dinner.

Hanako stays with Anna in the bathroom, cleaning up the dirt and debris. She then thanks Eikichi's family for being so considerate of them and treating them well.

Chapter 13
A month has passed since the giant Sagako appeared and destroyed the Busters' headquarters. While the group is in a motel, they go through the newspaper articles and Hanako discovers one about Higashino's death, listing it as a traffic accident. After learning of the disappearance of women in the Takeo area, the group heads out to investigate what they presume to be paranormal activity.

The area they arrive at is a viewpoint near the Nagasaki border, so the group splits up to investigate on their own. Hanako appreciates how Tae and Eikichi's relationship is getting better and better, and she feels more like siblings. Suddenly, Magatsuhi appears behind her, asking for her help. She mistakes her for a lost child and tells her that she is going to help her find her family, so she will stop crying. Subsequently, Hanako mysteriously disappears, and no longer responds to the radio.

Chapter 15
Anna and Hanako arrive accompanied by all the previously sealed Sagako to their aid. She explains to Tae and Eikichi that the Sagako had helped them escape thanks to Yuko's feelings being passed on to them. As Eikichi put a blanket on them earlier, the Sagako hatched from the onions. Eikichi asks if it's been that easy all along, but Hanako tells him that maybe Yuko's onion needs something more than that, and it's to listen to her brother's feelings.

Chapter 16
The group thinks they have defeated the Sagako spider, but a new form of this Sagako emerges from the dust. But Anna and Hanako did not arrive alone, since Hanako created a Sagako anti-spider cannon, with which they injure the curse.

Magatsuhi instead unleashes a spike attack that destroys all the Sagako and leaves the group in worse shape. Eikichi worries about Hanako, who is bleeding; however, she tells him that he must rely on his power to defeat the Sagako.

Chapter 17
It's been 5 years since Tae died, sealing the last Sagako. Hanako has become a well-known scientist around the world for her researches, and has even won awards for it.

On Tae's anniversary, she returns to Saga and makes a surprise entrance at the Hyodo house. She also witnesses how Yuko is released from the onion where she was and is reunited with her brother; she also helps Yuko cut the antlers of the Sagako she fused with. Without Sagako, the prefecture is at peace again, and the power of the onions has also disappeared.

Later, she comes to the graveyard where Eikichi and Jofuku are to celebrate their “promised day”.

Hanako Hakase/Historia