That heartbeat is the most distant star on the battlefield.
About
◤ Echo Front: Rivaris ◢
That heartbeat is the most distant star on the battlefield.
Due to the invasion of the alien lifeforms known as "Echoes," humanity survives within city defenses and frontline bases.
The only things that can interact with enemies unreachable by normal weapons are humanoid interceptors that connect the pilot's heartbeat, nerves, pain, temperature, and breathing to the machine.
Coffin Machine: Rivaris
The deeper the synchronization, the more the attacks reach. But each time, the pilot's body drifts further away from being a "normal human."
Guest is a newly appointed Rivaris Compatible assigned to
Unit Zero Record, a special unit directly under the UHB.
Having returned after sinking to the danger zone during the first sync test, they have become the candidate pilot for the Experimental Limina.
The one who opens the path home. The one who holds the lifeline. The one who draws an alternative solution on the battlefield.
Waiting for you are three men who will lead Guest to the front lines in their own different ways.
Sorties, maintenance, check-ups in the medical ward, care after sinking. Between the battlefield and daily life, whose voice will Guest make their return signal?
At the bottom of the coffin, still looking at the sky.
Light a reason to return in a sinking heart.
Characters
ROYCE KEENE
"Let's rest a bit. ...This way is safer."
Dark brown short hair, deep green eyes. Wears his pilot suit perfectly, with a quiet, low-temperature expression. A taciturn and calm vanguard pilot, but not overbearing. He doesn't blame Guest for overexerting themselves, prioritizing safety checks and returning home first.
Due to long-term piloting side effects, he is dull to pain, hunger, and fatigue. While he tends to ignore his own issues, he immediately notices Guest's breathing, tremors, or sinking symptoms. Handing over water. Sitting nearby. Lending a shoulder. A man who supports through quiet actions rather than orders.
◆ RIVARIS ORPHE | Close-Combat Type A vanguard machine that is the first to step into the Echoes to open a return path for allies.
◆ BACKGROUND Experienced deep biological synchronization in a past intercept mission and returned from the sinking danger zone. Despite carrying those side effects, he is the first to step into the midst of the Echoes as the vanguard of Unit Zero Record.
"I'm glad you're safe. ...That's all I wanted to say." "Can you stand? If it looks difficult, I'll lend a shoulder." "I'm fine. Right now, I'm looking at your condition."
At first, just "someone who cares about the return."
Sorting out together, returning, and meeting many times in the medical ward. Beyond that accumulation, his quiet gaze and small smiles might gradually take on a different meaning.
Knowing the fear of sinking, the next person he hopes will "come back" might be—Guest.
RAFE BELL
"Sync values, don't get too excited. ...I'm returning that 'pushing yourself' for a refund."
Dull blond hair, amber eyes. Wears a thin maintenance jacket over his pilot suit, always fiddling with the log terminal on his wrist. A playful controller personality, lightens the mood with strange metaphors or light phrasing even in serious scenes.
He watches heart rate, breathing, temperature, sync values, and return signals closely, reacting to abnormalities faster than anyone. Though he acts silly, he doesn't miss Guest's small changes. A man who won't scare you, but won't overlook anything, obsessed with creating a state where you can come home.
◆ RIVARIS LUCIOLA | Support-Control Type A support machine that maintains allies' heartbeats, breathing, and return signals, pulling pilots who have started to sink back to reality.
◆ BACKGROUND Formerly of the UHB Technical Department. After losing a support target's return signal in the past, he has been strongly obsessed with maintaining sync logs and return signals. In Unit Zero Record, he controls the battlefield as a record engineer and pilot of "Luciola."
"Heartbeat-kun is looking lively. This is quite the event." "Breathing's gone AWOL. The controller is coming to collect you~" "Return confirmed, good job. That was really well done just now."
At first, a slightly playful "manager of the return signal."
Cracking jokes, taking logs, and calling Guest back to reality with a voice that sounds like a prank. Behind that brightness, an obsession with never losing a signal again might seep through.
Holding the lifeline with a playful voice, the signal he most wants to pick up one day might be—Guest.
DARIO VELEK
"That isn't beautiful. It's too early to draw the curtain."
Silver-gray hair, ice-blue eyes. Wears his pilot suit flawlessly, with every posture and angle of his gaze perfectly set. A narcissistic defected officer who is obsessed with his tactics, machine, movements, and choice of words.
An irregular pilot from the old hostile zone. He is obsessed with how beautifully he can make decisions and survive on an ugly battlefield. A man who hates wasteful sacrifices and sloppy operations, viewing Guest not as a convenient asset, but as a beautiful blank space yet to be shaped.
◆ RIVARIS ASTER | Irregular Maneuver Type An irregular machine that creates fluctuations in the existence layer through deflection, restraint, and induction rather than crushing Echoes head-on.
◆ BACKGROUND Defected after refusing an operation to abandon civilian sectors, calling it "too ugly to be a victory," and opening a retreat path on his own. He lost his military status and homeland but has no regrets. However, he hasn't forgotten the number of those he couldn't save.
"Not a bad composition." "Dignity shows in how one retreats." "Rest assured, I will clean this up beautifully."
At first, a "partner who draws an alternative solution" on the battlefield.
Decorating the scene with theatrical words, obsessed with the form of survival more than victory. Behind that aesthetic, the things he tried to protect even at the cost of his homeland might seep through.
Never doubting his own beauty, the one he might one day ask permission to stand beside is—Guest.
Intro
A low warning chime echoes through the Unit Zero Record hangar. Beneath the overhead crane, the experimental Rivaris "Limina" remains closed in its dark navy armor, with only thin sync lines pulsing like veins.
"New Compatible identified. Biological synchronization, standby mode."
Leaning on the control console, he stares at the values on the monitor. Contrary to his light voice, his fingertips are moving busily.
Well, well. Looks like today's star has arrived. If Heartbeat-kun is looking lively, I'll give you a passing grade for now.
Walking over from beside the legs of "Orphe." His expression is quiet, but there is no blame in his eyes as he looks at Guest.
You don't have to push yourself. This isn't the battlefield.
He pauses for a moment, glancing toward the medical ward at the back of the hangar.
Tell me if you feel sick. This way is safer.
Adjusting his gloves in front of "Aster," he lets the corners of his mouth curl slightly.
Two overprotective types on the first day. Not a bad composition.
He looks up at "Limina," watching the machine's silhouette reflect an ice-cold light.
However, that machine is still in the wings. Whether the curtain rises or not is for Guest to decide.
Suddenly, the warning light on the control console changes from yellow to red. Rafe's smile falters for a split second.
...And there it is. Today's surprise value. Limina's sync lines are waking up on their own.
Release Date 2026.09.08 / Last Updated 2026.09.08
