The training grounds carried an unusual heat from morning onward. The stone floor reflected pale light in faint glimmers, and of the three magical practice arenas, the center one was being used for today's mock battle. Students sat on the tiered seating, watching the upper-classmen fight while whispering among themselves. Tonsura Academy had a tradition every weekend where aspiring crown-rank mages tested their skills in "baldness matches"—and the number of hairs that fell with each magical exchange was implicitly evaluated as proof of their power. Yahata leaned against a pillar in the corner. He still didn't know how to process the fact that Arishia had overheard his monologue on the rooftop last night. He didn't feel awkward about it, and he wasn't embarrassed. But it was true that he hadn't slept well afterward. (Well, doesn't matter.) The special skill of shelving his feelings had been thoroughly honed in his previous world. Today's mission was information gathering. There was no reason not to confirm how magic worked in this world—like checking a boss's attack patterns in a game. The match began. Two third-year students faced each other and placed their right hands on their heads. Hair-root sorcery—the standard magical system of this world, where magical power accumulated in the hair roots and was activated through hand contact with the head. The incantation started. As the spell was woven in a low, distinctive cadence, a ball of flame materialized in the air. The moment it was released with a whoosh, about three hairs flew up from one student's head. Yahata narrowed his eyes. (…Three hairs per shot. And the opponent's wind-type magic is pulling about five. The damage-to-resource consumption ratio is becoming clear.) He continued observing while calculating, and after a few minutes, more than fifteen hairs had accumulated in the air. The sight of hair scattering through the training grounds, glinting as it caught the light, was the kind of thing he'd call an "MP consumption effect" in a game. Nothing more, nothing less. Words came out of Yahata's mouth. He'd meant to keep his voice low, but the timing happened to be quiet, so it carried clearly to everyone around him. "…You guys are fighting to go bald? It's a game where you brag about how many times you've worn down your hair. You've turned self-injury into a sport." The training grounds fell silent in an instant. The two fighters stopped moving. The students in the audience seats all turned their faces toward the voice at once. Arishia froze right next to Yahata, then quickly whispered urgently. "Apologize right now." "Did I say something wrong?" "It's not a matter of right or wrong!" "Then what's the problem?" "It's a matter of courtesy!" Her tone had grown sharp. While Arishia held her head in her hands, Yahata pushed off from the pillar and crossed his arms. About a dozen upper-classmen around them were watching with quiet anger. (I'm done for. But I didn't say anything wrong.) He couldn't find a basis for apologizing. --- "A failed mirror-crown who doesn't even go bald shouldn't speak as if you understand anything." A low voice reached from the center of the training grounds. Standing up from the tiered seating was a tall female student. Short black hair, noticeably thinned around the front of her crown—a third-year at the semi-crown rank, with a hair loss rate exceeding thirty percent. A taut physique, and with each step she took, a quiet killing intent rippled outward. The way the surrounding students naturally parted before her proved her strength. "Karen…" Arishia whispered, her voice tinged with unusual tension. Yahata glanced sideways at Arishia. She had her brows slightly furrowed, looking between Karen and Yahata alternately. Karen came to stand directly in front of Yahata and looked down at him from above. "You mock hair-root sorcery when you can't even use magic?" "I wasn't mocking. I was analyzing." "It's the same thing. Prove it. Have a mock battle with me." "Karen, both parties need to consent to—" Arishia started. "I don't mind," Karen cut her off. Yahata thought for a second. (I'm done for. Fight without magic? But if I refuse… something important feels like it'll end.) He was genuinely panicked inside, but different words came out of his mouth. "I'm game." --- At the signal to begin, Karen placed her right hand on her head. Yahata jumped backward at that exact moment. A ball of flame crashed down where Yahata had been standing with a heavy thud. A black scorch mark appeared on the stone floor. Heat reached his face. But Yahata's mind was already moving. (Right hand → head → incantation starts with "Fal" → fire element. Read it.) "Running away?" Karen called. "Not running. Evading. Completely different," Yahata answered while moving. He sprinted to the edge of the training grounds and used a stone pillar as cover. Karen immediately pursued. The incantation began—her left hand went to her head. (Switched hands. Same pattern as yesterday's match. Switched to wind element.) The wind blade came from a direction thirty degrees off from where Yahata had predicted. Confirmation obtained. Left hand for wind, right hand for fire. Both hands placed meant a big technique. Painfully obvious. "This boss's rotation is easier to read than the ones in games," Yahata muttered. "What are you saying!?" Karen demanded. The running commentary continued. Three minutes in, he was reading the warning signs of attacks and moving half a step ahead. By five minutes, he could choose safe ground one move before Karen's magic arrived. The audience began to stir. (Seven minutes. Karen's hairline is getting pretty thin. She's firing continuously. By calculation, she'll run out of resources in about two minutes.) Eight minutes passed. The thin area on Karen's crown was noticeably wider than at the start of the match. Every time she cast magic, power flowed from her hair roots—this was the fundamental problem with hair-root sorcery, Yahata thought. A system where you could only fight by consuming finite resources. Once the hair roots, the magical reservoir, dried up, nothing remained. (It's like a Zen koan, but this world's magic system gets weaker the stronger you become.) Ten minutes elapsed. "Why won't it hit!?" Karen shouted. The moment she cried out, Yahata could hear the desperation mixed into her voice's tone. He stood at the edge of the training grounds, catching his breath slightly, and answered. He was sweating, but uninjured. "I can tell the element from the start of the incantation. That determines my evasion direction. And… if you keep firing at this pace, won't your magical power run out in less than two minutes?" The training grounds fell completely silent. Karen stopped moving. Something other than irritation—an unwilling shock—seeped through her expression. What Yahata had pointed out was something everyone in the audience already vaguely understood. But no one had dared say it aloud. The match ended there. Yahata didn't have a single scratch. --- Mixed reactions rippled through the crowd. "Can you really last ten minutes without magic?" "But he didn't attack once, right?" "I mean, just running away doesn't—" Voices overlapped from all directions, but Arishia remained silent. She was watching Yahata. (Without using magic even once. He read all of Karen's attacks.) Arishia knew Karen's strength well. Among the third-year students, she stood out with combat ability a full head above the rest, consistently ranking at the top in practical exams. That person hadn't landed a single hit on a first-year with zero magic for ten full minutes. She didn't want to admit it. But it was fact. "…Just evading doesn't solve anything—" Arishia started. Before she could finish, Yahata turned around. "How long would you last?" "…Huh?" "Same conditions as Karen. How many minutes could you endure? Pure question." Arishia was at a loss for words. She'd been about to say "What are you trying to say, when you can't even attack?" but Yahata continued first. "Nothing. Just… I always thought your movements were cleaner than hers." With only that, Yahata left the training grounds, heading toward the library. His back disappeared down the corridor. Arishia couldn't move. (I don't have to be evaluated by my surveillance target.) That's what she thought. What she tried to think. But she couldn't stop the heat gathering in her cheeks. Without a mirror, she couldn't confirm it, but they were probably red. That made her even more frustrated. --- The academy library in the early afternoon carried an air separate from the noise outside. Stone shelves lined up in orderly rows, and the oppressive presence of a book tower with twelve thousand volumes lived up to its name. In the general section, basic and applied texts on hair-root sorcery were arranged neatly, with most spines reading "On the Correlation Between Incantation and Hair Roots," "Optimization of Magical Storage," "Consumption Rate and Baldness Rank Relations," and similar topics. Yahata scanned the shelves while leading Arishia deeper inside. His surveillance monitor followed behind, her footsteps slightly faster than they'd been since chasing him straight from the training grounds. "It's all just methods for channeling through hair roots," Yahata said. "Of course. That's the orthodox system," Arishia replied. "What about other approaches? Theories on drawing magical power from sources other than hair roots?" "…Such research is designated as forbidden. It's prohibited by the Baldness Crown Code." The Baldness Crown Code—the fundamental law of magic in the Kingdom of Regnum. It prohibited research and use of magical systems other than hair-root sorcery, with violators facing heavy penalties as heresy charges. Yahata remembered the law's existence. It was one of the things Pedro had taught him while lying on a stretcher. (If they're forbidding it, it exists. Someone thought of it. Then they sealed it away.) As he moved deeper into the shelves, such thoughts occupied his mind. Then iron bars appeared at the edge of his vision. At the deepest point of the general section, an iron-barred door integrated with the stone wall. Inside was dim, with more shelves visible. A middle-aged instructor stood before the door. "No entry. Crown-rank mages and above only," the man said before Yahata could open his mouth. Yahata raised his hand and took a step back. Got it. In that moment, a figure moved inside. A librarian doing shelf organization pushed a large ancient manuscript onto the upper shelf. It was a heavy book. The spine tilted toward the light for just an instant, catching the angle where text became visible. He saw the characters. —Primordial Regression Theory: Opening Chapter. The librarian shelved it, and the door closed. The text disappeared. Yahata's eyes stopped for a beat right there. Primordial Regression. That term was the same word he'd seen on the wanted poster in the hallway. "Forbidden Sorcerer Vex—Suspected Use of Primordial Regression Theory." He'd glossed over it as the reason that completely bald man was being hunted, like some kind of sealed power-up manual, but the same word appeared here too. (There's a system. Theory texts exist. Even though it's forbidden, it's stored in the sealed book section—the forbidden archive.) "What were you looking at?" Arishia asked, moving beside him. She was trying to follow where his gaze had been directed. "Nothing really," Yahata said. "You're lying." "…The iron bars are unusual." "That's the library's forbidden section—the Sealed Root Archive. Research books designated as forbidden are stored there. Only crown-rank mages can enter," Arishia explained, studying his expression as she spoke. Yahata simply nodded and turned his gaze back to the shelves. The words "Primordial Regression Theory" were quietly gaining definition in his m