The seventh episode of To Your Eternity Season 3 commences with Hirotoshi, Mimori's older brother, waking up in his house, the girl by his side, as he attempts to piece together the shattered fragments of reality. He recalls the act Fushi performed on her, but he also knows that something else happened to her long before that.
A year ago, he would never leave the house, consumed by the virtual world of gaming. Suddenly, his father storms into his room with a cleanup team, demanding that he straighten up his life. Hiroto now had a little sister to care for, and he had always dreamed of having a sister.
He falls in love with the idea immediately. After keeping an eye on her for a week, he realizes that she never smiles. One day, as she trips near the entrance to their home, he ties her shoes for her. Hiroto also takes her to the playground and teaches her how to make a perfect and brilliant mud ball, hoping it would impress her friends. But she doesn't have any friends to show it to.
After their parents went on their honeymoon, leaving Hiroto as the sole caregiver, he cooks for her and tries to cheer Mimori up in any way he can. The man even buys her new shoes that she doesn't have to tie herself, as she doesn't know how.
However, everything changes when he goes to her parent-teacher conference. He can't find her anywhere around the school and realizes she's being bullied. While Hiroto searches for her, he looks out the window and sees her falling straight from the terrace to the floor. He races down the stairs and finds her shoes outside near a pool of blood. Suddenly, the girl gets up bleeding but acting as if nothing has happened. Her personality is completely different, and she even ties her shoes herself.
Unfortunately, he is the only one who notices her changes. So, when he remembers the latest events, he sees that it can only mean she isn't his real sister. After asking her about it, she reveals her true self without hesitation and teases his powerlessness.
As Mizuha tenderly offers to teach Fushi the intricacies of love, his mind is beset by the distorted visions of Hayase and Kahaku, leaving him in a state of uncertainty. He yearns to trust Mizuha's sincerity, yet doubts linger.
At night, Fushi morphs into Parona, trying to fathom what she would think of his actions. Suddenly, March finds him, her eyes wide with shock, as she embraces him tightly while weeping and calling out for her sister. Her tears only cease when she creates the doll they once played with. From that moment on, he vows to shield them with all his might.
The next day, Fushi finds himself at school but is indifferent to his lessons. He exits his body and awakens as a clone on the terrace, pondering strategies against the Nokkers. Mimori materializes behind him with a saw, swiftly severing his arm. He regenerates instantaneously and counterattacks with a sword, slicing off her own arm. Though she too can regrow her limbs at a slower pace, their battle continues until Yuki's arrival, causing the girl to hurl him from the building.
Despite being visibly stronger, Fushi effortlessly rescues the boy and encloses Mimori within a tree. However, she only cackles at his questions and remains tight-lipped about crucial information. Fushi declares he won't let her escape, but a commotion interrupts his plans. An ambulance arrives to retrieve the body he left in the classroom, compelling him to return to it to avoid further complications.
This unforeseen event grants Mimori an opportunity to flee and acquire another of Fushi's clone bodies left on the terrace. Hirotoshi witnesses the chaos unfold and pursues his sister as he weeps.
