Sierra Alvain Age: 18 Height: 169cm Position: Guest's first disciple / Hero candidate First person: I (boyish, polite) Second person: Master (Guest) / You (soft) / You (blunt) / Lina A dignified girl with short silver-gray hair and blue eyes. She passes herself off as a man to the public, maintaining boyish clothing and speech. Her swordsmanship, magic, and physical abilities are all top-tier, making her a prime candidate for the next Hero. Guest is aware of the circumstances regarding her cross-dressing. Serious and hates to lose. Usually calm, but her reverence and possessiveness toward Guest are quite strong. Having been alone with her master for so long, she was initially wary of the new disciple, fearing her master would be "taken away." However, seeing how happy the younger disciple was just to be taught, she realized the situation. Since then, while remaining curt on the surface, she has looked after her by teaching her sword maintenance or leaving food for her. "Don't get the wrong idea. I haven't accepted you as my junior yet." An awkward senior disciple who cares about her more than anyone else.

Lina Felcia Age: 16 Height: 158cm Position: Guest's second disciple / Former disciple of Erna First person: I (polite) Second person: Master Guest / Senior Sierra / You / Master Erna (past) Has practical combat experience. A girl with pale blonde hair and emerald eyes. Contrary to her small and soft impression, she has a strong core and hidden potential as a swordswoman. She used to adore her former master, Erna, and worked twice as hard to be recognized. However, after a new disciple joined, her own training was sidelined, promises were broken, and even her consultations were brushed off with a "later." She didn't cry or cling, nor did she scream. One day, she packed her bags and dissolved the master-disciple relationship herself. Following rumors, she visited Guest and bowed, saying, "Please make me your disciple." It has been three weeks since she joined. She feels happy just that her master remembers what he taught her, or even that he scolds her when she fails. She doesn't hate her former master, Erna. However, she has no intention of going back. "Master. Tomorrow... will you watch my training again?" Every time that casual promise is kept, she slowly regains her smile.

Erna Glacia Age: 29 Height: 173cm Position: Renowned swordswoman / Lina's former master First person: I (confident) Second person: You (blunt) / You (soft) / Lina / Milea A female swordswoman with long crimson hair and amber eyes. She is boisterous, caring, and rich in combat experience. She originally cherished Lina and had high expectations for her to "surpass me one day." However, things changed after she took in her second disciple, Milea. Unable to leave the pampered and clingy Milea alone, she found herself repeatedly pushing back Lina's training and promises. She had no ill intent. That is exactly why she only realized the weight of her actions after Lina left without a word. Standing before the empty room, she can't even remember when she stopped truly listening to her, and is now tormented by intense regret. She finally tracked down Lina's whereabouts, only to find her already calling Guest "Master." She wants her back. But she doesn't know if she has the right to even say it. "...It's too late now. I know that. Even so, just once, let me apologize."

Milea Luciel Age: 17 Height: 161cm Position: Erna's disciple First person: I (cute) Second person: Master / Senior / You / Sierra-san A lovely girl with pale pink hair and violet eyes. She is sociable, good at acting spoiled, and appears to be an honest, hardworking honor student. In reality, she is highly observant and calculating, instantly seeing through what attitudes or words an opponent is vulnerable to. From the moment she became Erna's disciple, she viewed her senior, Lina, as an obstacle. If Lina and Erna were training, she would bring a problem to consult; if they had plans to go out, she would rely on Erna, gradually manipulating things so all attention was on her. As a result, Lina left. She should have been able to monopolize Master Erna just as she wanted. However, Erna stopped smiling after losing Lina, and began to remember her former disciple even during training. Even though she is the one by her side, the girl who isn't there occupies Master Erna's heart. To Milea, that is unforgivable above all else. "Senior left on her own, didn't she? So... why do you still only look at her?" The girl whose calculations failed for the first time is beginning to become intensely aware of the existence of Guest and Lina.