February 24th is a date that holds a special significance- this year it marks the thirteenth anniversary of the first Heterodyne appearance, and for Ibuki, the thirteenth anniversary of her father’s death. As always, she commemorates by taking the day off to visit his grave, leaving the others in the office to speculate about just what she is doing.
After visiting the Sakurada family grave, Ibuki goes to lunch with her mother and stepfather at an Italian restaurant. Professor Momoi tries to strike up a conversation with Ibuki, only to be met with monosyllabic responses. The situation deteriorates from there, with Ibuki drinking cup after cup of black coffee against her stepfather’s advice, whilst Momoi ends up talking business to a co-worker who is also in the restaurant.
Finally, Ibuki is given an escape from the awkward situation by an emergency call from work. It may be her day off, but all of Dai-Guard’s pilots need to report in when there is a Heterodyne alert. As Ibuki prepares to leave, Professor Momoi wonders how much longer she intends to do this- doesn’t she realise that he and her mother are worried sick about her? Listening to his words, Ibuki is pushed over the edge when Momoi brings her father into the conversation, and she angrily storms out.
Much to Saeki’s distress, Ibuki is twenty-six minutes late in reporting to the hangar. As he begins to lecture Ibuki, Akagi tries to defend her, but Ibuki stops him from mentioning that it is the anniversary of her father’s death.
The Heterodyne alert is soon cancelled, and Ibuki heads to the locker room to change out of her pilot suit, only to end up running into Domeki. Domeki has just realised that Ibuki is the daughter of Eijirou Sakurada, the man who made the first research into dimensional quakes- the one who first predicted the Heterodynes.
Over coffee and noodles, Domeki explains to Ibuki how she came to be interested in Sakurada’s research. Even as an infant, her genius intellect meant that most subjects were so easy for her that they quickly became dull. When the Heterodyne appeared, they were like a dream come true- something that she knew nothing about. Since then, she became determined to learn everything she could about them, and where better to start than by reading Sakurada’s book?
As she drinks her coffee, Ibuki reminisces about her father, and the way he used to like black coffee- which is why she drinks it so often. In her eyes, he was a hero; he was the first one to predict the Heterodyne, but no one listened to him when he tried to warn them. Maybe if they had paid more attention to his research, he wouldn’t have gone out on the survey ship that found the first Heterodyne- and he wouldn’t have been killed.
Ibuki explains that she has dedicated her life to avenging her father’s death and continuing his work, but Domeki seems unimpressed. Having read Sakurada’s her book, she has quite a different sense of his motivations. As a researcher into parallel dimensions, Sakurada’s work was potentially ground-breaking, but only if he could prove his results to his colleagues. The appearance of a Heterodyne would validate his theories, and in Domeki’s opinion, that was all he was concerned about. He wasn’t trying to warn people, or save them, he was only looking for scientific glory.
Ibuki is unwilling to believe Domeki’s words, but before they can talk further, Ibuki is called away- a Heterodyne has appeared on the coast. Shaped like a giant floating larva, this Heterodyne is almost identical to the very first Heterodyne that appeared thirteen years ago. As Dai-Guard marches in to tackle it with the Knot Punisher, Ibuki finds herself lost in memories of the past, now coloured by Domeki’s pronouncement that her father was anything but a hero. Distraught and distracted, Ibuki is unable to contribute as Dai-Guard’s navigator, and the team suffers as a result. Without Ibuki’s input, Akagi’s attack with the Knot Punisher is off target, and even though he smashes the Heterodyne’s body, the original fractal knot drops into the sea, unharmed.
Akagi’s off-target attack also had another effect- the Heterodyne was able to emit a corrosive gas that has severely damaged to Knot Punisher. It will take at least a week to repair it, and with the original fractal knot still undamaged, the Heterodyne is almost certain to reappear before that. In the meantime, the pilots will be on standby alert, and Domeki decides to use the opportunity to help Ibuki see the truth. Having dug up some footage of Sakurada’s last mission, she shows it to Ibuki. Rather than running away like everyone else when the first Heterodyne appeared, Sakurada was insanely happy and excited to see it.
In her self-appointed role as psychiatrist, Domeki suggests that Ibuki always knew the truth about her father, but she blocked it out and tailored her memories to create a more heroic image that she could honour and admire. Now, these false memories have become an integral part of Ibuki, but if she wants to find true happiness as Ibuki Momoi instead of Ibuki Sakurada, she will have to learn to let them go and accept the truth. As yet unready to acknowledge that Domeki is right, Ibuki leaves.
The Heterodyne wastes no time in creating a new body, and Dai-Guard is sent out once again to attack it. With the Knot Punisher out of commission, a spiked Drill Arm is equipped in its place. As the team head into battle, Ibuki seems to be back to her old self, doing her job as navigator as efficiently as ever- at least until she looks at the Heterodyne head on. The sight triggers her memories of the first Hetoerdyne attack, and Ibuki once again becomes lost in the past. Even as Domeki tries to send her the data they will need to destroy the creature, Ibuki is lost in her past memories. Only now, as she relives them, she is overcome with the crushing realisation that Domeki was right. And if that is true, and her father never was the hero Ibuki made him out to be, then there was never any reason for her to fight the Heterodyne in the first place.
Crushed, Ibuki physically and mentally withdraws from battle. Fighting alone, Akagi and Aoyama cannot defend against the Heterodyne, and Dai-Guard begins suffering major damage. Watching from the sidelines, Saeki frantically calls to the pilots, and eventually Ibuki awakens to find herself in a very real nightmare. Half-destroyed, Dai-Guard is immobile on the burning battlefield, whilst both Akagi and Aoyama are unconscious. Is this the end for Dai-Guard and its pilots?