At the office, Tanigawa is the centre of attention, thanks to all the tasty snacks she painstakingly acquired for the rest of the team (what she neglects to mention is that it was Ijyuuin who did all of the donkey work). However, whilst the rest of the team take a break to eat, Akagi and Ibuki remain hard at work- at least until the others switch the news on. Whilst Akagi silently fumes as an interviewed expert labels Dai-Guard’s pilots as incompetent, Ibuki is more interested in the next report- about an old park that is in an area due for redevelopment.
Meanwhile, in his office, Shirota is once again explaining to the army that taking control of Dai-Guard by force would not reflect well on them. In the face of the general’s growing impatience, he is quick to reassure his superior not to worry- Shirota is researching an alternate plan.
On the way home, Ibuki passes by the old park, and spots a little girl waiting there in the falling snow. The girl, Yuka, is waiting for her father, just as Ibuki used to when she was younger. After warming Yuka’s hands, Ibuki offers to play with her- they could build a snowman together. Recalling her own past, Ibuki remembers how she built a snowman whilst waiting for her father, only to be disappointed when it fell apart. Fortunately, her father showed up shortly after that, and helped her to build a bigger and better snowman.
Seeing the new snowman cheered young Ibuki up, until she noticed that her father didn’t seem too happy. Explaining that he was depressed because no one would believe the results of his research, Ibuki’s father let himself be cheered up by his daughter, and in return, gave her a copy of his textbook- “An Introduction to Space-Time Resonance.”
Of course, as the snow melted, so did the snowman that Ibuki and her father made. Young Ibuki was very upset about this, until her father explained that the snowman wasn’t really gone- from snow he melted into water, before evaporating to rejoin the clouds in the sky, so that he can fall again as snow or rain.
Yuka listens to Ibuki’s recollections for a while, until her father arrives to take her home. Returning to her own home, Ibuki is asked by her stepfather why she is late, but refuses to answer, instead going straight to her room. Spotting her father’s book on a shelf, she remembers the day he left to go and prove his theories were correct. Although he promised to return, he was never able to keep his word- instead, he was killed in the very first Heterodyne attack. Young Ibuki didn’t want to believe that her father was dead, but even she could not hope for his survival when, from afar, she saw the army drop an OE bomb on the Heterodyne.
Ibuki is not given the chance to dwell in the past for long, however, for the next Heterodyne has appeared. Shaped like a huge horizontal star with 4 legs and a cone-like ‘tower’ at the top, this latest Heterodyne has the deadliest ability yet- everything it touches is simply erased from existence.
Using electromagnetic waves, the army begins luring the Heterodyne to the redevelopment area, hoping that once it is there they can plan their next move. And part of that next move is keeping Dai-Guard out of the fight; as physical contact with the Heterodyne is out of the question, Shirota believes the giant robot should remain on the sidelines.
Dai-Guard’s pilots are far from content to sit and wait, however, especially when they hear that two civilians are still caught in the path of the Heterodyne- Yuka and her father. The army’s best efforts are having little effect on the Heterodyne’s course, so Akagi and the others plan to buy enough time for the civilians to escape. Even Shirota’s pronouncement that they cannot win against the Heterodyne is no deterrent- winning is less important than saving lives.
Having injured his leg, Yuka’s father is unable to move, and with Yuka refusing to leave him, it looks as if both will be erased. Fortunately, Dai-Guard reaches them just in time, and, by using a giant girder, they are able to push the Heterodyne back. Unfortunately, every second the girder remains in contact with the Heterodyne sees precious metres of it eaten away. Dai-Guard will only be able to hold it back for a limited amount of time.
An army truck arrives to rescue Yuka and her father, but even as they leave, the last part of the girder disappears, and the Heterodyne begins erasing Dai-Guard’s arm as well! Finally, the robot is thrown back, but the shock of the impact leaves them immobile- and directly in the path of the Heterodyne.
Moving ever forwards, the Heterodyne erases another building, but as the water container on top of the building is dissolved, Ibuki notices that the water inside is not erased- it just splashes all over the Heterodyne, as does the falling rain. Remembering how her father talked about solids and liquids when her snowman melted, Ibuki realises that the Heterodyne only dissolves solid materials- and that might just be the key to beating it.
Shirota immediately wants to ask the army to step in with some toxic solution, but Oosugi asks him to wait and give Dai-Guard a chance. Whilst Akagi sacrifices the rest of Dai-Guard’s arm to keep the Heterodyne back, Aoyama manages to get the robot functional again, and they manage to push themselves up and back out of the way.
In the meantime, Oosugi has spotted a lorry container filled with acid. Contacting Akagi, he instructs the pilot to use it on the Heterodyne. With its one remaining good arm, Dai-Guard picks up the lorry and hurls it at the Heterodyne. The outer container is immediately erased and the acid is released- in moments, the majority of the Heterodyne is dissolved, except for a single red hexagon.
Even as the pilots relax, however, it becomes clear that the battle isn’t over yet. The red hexagon begins replicating itself, as if to form a new Heterodyne. Before that can happen, Ibuki tells Akagi to stamp on the hexagons, and Dai-Guard crushes the last of the Heterodyne.
Whatever the significance of the hexagons, their presence certainly pleased the watching genius in Tech Division- a young woman who also happens to possess a copy of the book Ibuki’s father wrote. But not everyone is pleased by this outcome; Shirota in particular doesn’t seem too happy about how close the pilots came to losing Dai-Guard, their one line of defence against the Heterodyne. And Director Nishijima isn’t pleased that they risked the robot at all, given that 21st Century Security had no business concerns in the attacked area. Ookuchi is sure he did the right thing, however- sending out Dai-Guard not only earned them a commission, it saved innocent lives.
Thanks to Ibuki’s memories, Dai-Guard won the day once again, but at army HQ, Shirota reveals a plan that may mean the end of the robot’s days in the spotlight. An old Dai-Guard prototype lies unused in the army hangar, a perfect starting point for them to build their own giant robot…