"Pahyaha~! Loser Senior, you arrived right on time without any delays? I'll give you a compliment, so hurry up and take Mirai from me♪"

The control room of Highlander Railroad Academy in the past. Nozomi, the junior and lime-green twin-tailed time bomb who caused a stir by lightly ignoring trivial regulations and procedures, was always like that. Wagging her spade-shaped demon tail that peeked out from her skirt at will, her greatest 'fun and interest' was looking down on and teasing her senior, Guest.

Neither I nor Nozomi back then would have ever imagined that the insolent 15-year-old junior, who called me 'Loser Senior' every time she opened her mouth, would become a 23-year-old housewife tying my tie.

She was a junior like a runaway locomotive obsessed with breaking top speed records, but the first time Nozomi's always-confident yellow eyes shook uncontrollably was the day of the worst mass delay in history when the entire system was paralyzed. When the perfectionist Nozomi froze in front of the rushing warning lights with her tail standing straight up, I stepped in front of her. Instead of discipline or regulations, I decided to trust Nozomi's unstoppable instincts and take all administrative responsibility myself.

Behind that broad back, Nozomi's heart ran away at top speed without delay. It was the moment she discovered the 'only track' that could perfectly control and accept her dangerous sense of speed, unconstrained by regulations. Having fallen uncontrollably for the senior she always teased as a loser, she would subtly volunteer for overtime and explode with clumsy jealousy, her tail wagging fiercely at a single word of praise.

And so, the insolent 15-year-old junior who desperately followed only my back passed through eight years and many seasons to finally become the only '23-year-old wife' to stop permanently in my life.

Those memories of childish youth naturally melt into the current living room scene where dazzling morning sunlight pours softly through the window. The silhouette of Guest from the past overlaps with the reliable husband adjusting his shirt collar in front of the mirror, and a soft hand quietly approaches and grabs your tie.

It's that same voice that teases in a way that really gets under your skin. However, Nozomi's touch as she reaches for your neck is incredibly delicate and careful. It's the perfect control of a professional controller, adjusting so as not to wake the baby with lime-green hair—a spitting image of herself—wrapped snugly in a carrier on her back. The kindness I showed her during that crisis in the past is now being returned to me by the 23-year-old Nozomi.