As the Self Defence Force begins clearing up the damage caused by the Heterodyne in Hokkaido, the arrival of Domeki in Sapporo brings some tentative good news. The legislation that will allow the Self Defence Force to aid in the battle against the Heterodyne has finally been passed, and will come into effect at twelve o’clock the next day.
Until that time, however, the Self Defence Force isn’t about to defy orders by attacking the creature, especially not when a foreign fleet is approaching Japan. Not only is the foreign fleet intent on capturing the Heterodyne rather than killing it, but the Self Defence Force is more concerned with the potential threat from the fleet than the actual threat from the Heterodyne. It is clear they are not going to help out, but there is nothing the team can do.
With nothing else to do, Akagi plans to go and sit in the Guard Fighter (his section of Dai-Guard), but he is in for an unpleasant surprise. When Ishihara came to see him after their last battle (see last episode), he stole Akagi’s Dai-Guard access key-card, and now he is using it to take the Guard Fighter. Realising the trouble they will be in if Shirota finds out what has happened, Akagi resolves to go after Ishihara himself.
Elsewhere, Aoyama is trying to convince Arisa to help them lure the Heterodyne to a place where Dai-Guard can fight it. The team has figured out that the Heterodyne is attracted to temperature gradients- it uses heat to supply itself with energy, leaving only when the energy source has dropped to the same temperature as its surroundings. All they need now is somewhere capable of producing a “hot spot”, and Arisa has the contacts and local knowledge to find them one. Arisa doesn’t seem too inclined to help, however; she still feels angry with Aoyama for running away from his responsibilities by breaking the Snow Festival contract.
Aoyama is beginning to despair of getting through to Arisa, but Nakahara is still willing to give it a try. She visits Arisa at work and tries to convince the other woman that she is mistaken about Aoyama- it is not that he runs away from his duties, but rather that he has a sense of the things that really matter. If he sometimes has to sacrifice something, then it is only for the sake of something more important.
Nakahara’s words don’t seem to be having much effect on Arisa, but as she goes to leave, Arisa hands over papers detailing a high temperature research facility in Ishikari. It seems that Aoyama really did get through to her after all- she has already talked to one of the professors there and told them to expect the Dai-Guard team.
Domeki and the others are delighted to hear about the facility- its use of geothermal energy to heat frozen soil is just what they need. However, they also need Dai-Guard and its pilot, and right now, Akagi is out in an ANPO helicopter, chasing after Ishihara and the Guard Fighter.
As Akagi follows him, Ishihara reveals that his plan is to attack the Heterodyne with the Guard Fighter. When Akagi reveals that the fighter isn’t actually equipped with any weapons, Ishihara is not deterred- he will ram the creature instead. The Guard Fighter will most likely be destroyed in the impact, but Ishihara doesn’t care- it will make for one last blaze of glory to compensate for his earlier mistake. For Ishihara was the one who accidentally locked onto the foreign scout plane when the Self Defence Force first tried to attack the Heterodyne- and the guilt he feels over his actions delaying the legislation amendment have driven him to this point.
Akagi is unwilling to see his friend sacrifice himself, however, and moves his helicopter between Ishihara and the Heterodyne- if he wants to die, then he’ll have to take Akagi down too. Unable to pull away in time, Ishihara flies into Akagi’s helicopter, and they both crash.
Leaving their downed craft, Akagi and Ishihara start moving towards each other across the snowfield. Akagi tries to explain to Ishihara that his perspective is mistaken; building snowmen and taking care of disaster relief are not secondary functions of the Self Defence Force- saving lives should always be more rewarding and important than fighting and killing.
Having said his piece to Ishihara, Akagi has to take the Guard Fighter and leave his friend- Aoyama has called to tell him about the plan to lure the Heterodyne. Using the research facility’s high temperature generator, they have heated a section of earth; now all they need to do is assemble Dai-Guard and wait for the Heterodyne to arrive.
Appearing right on schedule, the Heterodyne begins drawing all the heat out of the area, and surrounding itself in its customary shell of ice. Akagi arrives shortly afterwards, and the three separate sections of Dai-Guard quickly combine.
Unfortunately, after the impressive assembly of Dai-Guard, things rapidly go downhill. The Heterodyne hits the robot with a wave of snow, and in short order Dai-Guard’s legs are frozen in a block of ice, leaving the robot unable to move. Things look hopeless, until a surprise helping hand arrives in the form of the Self Defence Force. Taking up their picks and flamethrowers, the men who were formerly building snow sculptures now turn their hands to digging Dai-Guard out of the ice. And, perhaps swayed more than a little by Akagi’s speech, Ishihara arrives to help too.
As Dai-Guard equips the Knot Punisher, the men continue their work, until finally enough ice is chipped away for Dai-Guard to break free the rest of the way by itself. Pulling its legs out of its icy confinement, Dai-Guard runs towards the Heterodyne, but they have left it just moments too late. Having drawn all the excess heat out of the warmed soil, the Heterodyne breaks free of its ice shell and flies away.
However, all is not lost just yet; whilst everyone was hard at work, the clock has passed twelve, and that means that the new legislation has now come into effect. The Self Defence Force now has the authorisation to help with the attack, and two fighter planes have been dispatched. On Saeki’s orders, the planes fire on the Heterodyne, destroying its wings. All that is left is the spherical core, which falls directly towards the ground. Knot Punisher at the ready, Dai-Guard runs towards the Heterodyne. Firing upwards, Akagi hits the fractal knot and shatters the Heterodyne.
The team’s time in Hokkaido is almost over, but Aoyama makes time for one last coffee with Arisa. Whilst Nakahara unobtrusively eavesdrops from the bar, Arisa admits that Aoyama has changed, but even back when he left, he wasn’t such a selfish person- she now knows that the reason he went back to Tokyo so quickly was to take care of his sick mother. Now, he must go there again, but this time, Arisa isn’t angry, for she finally understands Aoyama a little better.
After Aoyama says his goodbyes and leaves, Nakahara tries to sneak out unobtrusively, but Arisa is well aware she is there. In an aside to the other woman, she remarks that, years ago, Aoyama labelled himself a ‘bargain’ because in the future he would turn out to be a great guy. And it looks like that was one promise he was able to keep.
The impact the team had on Hokkaido certainly won’t be forgotten, not by Arisa, nor Ishihara. In fact, how could anyone forget when the centrepiece of the town is a giant snow Dai-Guard centrepiece, complete with Knot Punisher pointing up into the sky?