We found ourselves in an exitless room surrounded by mirrors, with an atmosphere that clearly signaled an impending boss fight. Wondering what our next move should be, I watched as the pedestal that had held the Holy Lantern back in the first room materialized in the center of the chamber.
As I approached it, glowing letters formed in midair.
"The Mirror Monster approaches. Place the Holy Lantern upon this pedestal once and take it up again, and you shall be able to focus and unleash the holy light into a single point. Aim with the red guiding light, and if you strike the Mirror Monster with the concentrated light three times, the fearsome monster shall return to the heavens."
I see. So these were the rules for the boss fight. Going by the description, it looked like I'd be able to fire something resembling a laser beam.
Aim with the red guiding light, huh... It would probably project something like a laser pointer. Using that, I'd have to find our target among all the mirrors in the room and blast it with the laser. Land three hits, and we win—something along those lines, right?
"However, concentrating the holy light is a double-edged sword... Once discharged, it cannot be used again until light fills the lantern once more. Take care not to miss your aim."
Though the warning was phrased somewhat vaguely, I could easily picture the mechanics. Since the fight required landing three strikes, it would likely play out in multiple phases. And presumably, the lantern's laser could only be fired once per phase.
While the first lantern had specified its cooldown in seconds, this one used the abstract phrase until light fills it, paired with a warning not to miss... If I whiffed a shot, taking a hit from the Mirror Monster was almost certainly guaranteed.
"The divine protection of light abounds. For now, you may nullify up to three of the Mirror Monster's attacks. However, you cannot endure a fourth."
Our margin for error was also three... No, if we were safe up to three times, that meant getting hit a fourth time would mean game over.
"...Looks like this is going to be quite a serious battle."
"Y-Yeah. It feels like the fight will start as soon as you set the lantern on the pedestal and pick it back up, right?"
Nodding with a tense expression, Hina-chan glanced around uneasily. The laughter that had echoed ever since we entered the room had died down, replaced by an eerie stillness like the calm before a storm. No wonder she was frightened.
Still, that aside... there really were a lot of mirrors. Weren't there close to fifty of them? Covering all of them on my own would be an uphill battle.
Hina-chan was terrified, and I wanted to get us through this as smoothly as possible, but... Just as that thought crossed my mind, I felt Hina-chan let go of my arm. When I looked back at her, I saw that despite her slight trembling, she had balled both hands into tight, resolute fists.
"Hina-chan?"
"K-Kaito-senpai! I'll watch the right half! Please keep an eye on the mirrors on the left!"
"That'd be a huge help, but are you sure you're okay with that?"
"Yes! I'm scared, of course... but up until now, I've been relying on you for everything, Kaito-senpai. I want to pull my weight too!...Ah, but please keep holding my hand... because I really am scared."
Seeing Hina-chan muster her courage to help out brought a soft smile to my face. She was timid enough to know it all too well, yet she was still determined to do her best and lend a hand because we were at the attraction's climax.
Honestly, this was a massive relief. Trying to watch nearly fifty mirrors alone versus splitting the load down the middle made a world of difference.
"All right, let's do this together and clear it."
"Right!"
I set the lantern down on the pedestal and used my free hand to gently pat Hina-chan's head. Then, clasping her hand in mine, we exchanged a nod.
"...Okay, here goes. I'm picking up the lantern."
"B-Bring it on!"
Encouraged by Hina-chan's spirited response—which sounded surprisingly confident despite how scared she clearly was—I lifted the lantern once more. Sure enough, a red laser sight projected onto the mirror directly ahead.
The beam seemed to extend straight forward like a crosshair. The red dot was sharp and vivid, so aiming wouldn't be an issue.
"Ahahahahaha!"
Right on cue, picking up the empowered lantern triggered the boss battle, and an ear-splitting laugh resonated throughout the chamber.
In the very next instant, reflections of Hina-chan and me wearing sinister smiles appeared across dozens upon dozens of mirrors.
"Eek...! I-I'm okay. Something like this is nothing!"
Those reflections clearly weren't mirroring our present actions. None of our reflections were holding hands, and every single one faced dead ahead.
However, because every mirror showed the exact same image, it was still impossible to tell where the Mirror Monster was hiding.
"Hina-chan! I think one of our reflections is going to change!"
"U-Understood! We just have to find that one, right?!"
The round had likely already begun. Even though all the reflections were just grinning creepily for now, a distortion was bound to appear in the mirror harboring the Mirror Monster.
"Ah, Kaito-senpai! Doesn't the reflection of you in that mirror over there look a little bigger?!"
"Ngh...! That's the one! Got it!"
Following Hina-chan's pointing finger, I saw that our reflections in that particular mirror were indeed slightly larger than the ones flanking it... No, they were probably inching closer to the foreground, which made them look larger than the rest.
"Aaaaggghhh?!"
Lining up the reticle dead center on that mirror, I pressed down on the stone. A blinding burst of light flared out, immediately followed by the Mirror Monster's agonized shriek, and every last reflection of us vanished from the glass.
Bullseye. That was one down, two to go... Having made it this far, I'd love to pull off a flawless victory if possible, but we'd see how things played out...
Mirror Monster: "Yes, precisely that... Put simply, Hina had been protected by Kaito every step of the way. She may dislike scary things, but deep down, she still wanted to be useful. However, Kaito was the one holding the lantern, and he was almost always the first to spot the anomalies. Yet in this boss room, the sheer number of mirrors makes it obvious that one person can't cover them all. Factor in the knowledge that this is undeniably the attraction's grand finale, and it was entirely predictable that she would summon her courage and offer to cooperate."
Serious-senpai: "N-No way... Are you telling me you calculated all of that...?"
Mirror Monster: "Achieving something through teamwork is a sweet, intoxicating experience. Hina's mood is particularly easy to elevate, and she is remarkably proactive when it comes to physical intimacy with Kaito. By manifesting on Hina's side in the opening move and letting her discover me, I gave her a sense of accomplishment—the feeling that she truly made a difference. Once the boss fight is over and she's riding high on that emotional peak, what kind of impulsive move do you think she'll make next...? You see where this is going, don't you?"
Serious-senpai: "...At this point, you're not even a boss, you're just a monster of romance..."