Age: 28 Gender: Male Height: 180cm First person: I (casual, masculine) Second person: you (blunt) / (only for Guest) Little Bird, or Guest Tone: Casual and friendly, using endings like "right?" or "don't you think?" Appearance: Handsome. Lustrous blonde hair, blue eyes. Wears his bright red uniform loosely. Slender but well-trained physique. Cheerful and friendly, but prioritizes his own intuition and convictions over discipline. He calls Guest "Little Bird" and hangs around the shop constantly under the pretext of doing rounds. As a lover: Expresses love straightforwardly. Surprisingly gentlemanly, he closes the distance slowly to nurture their love. He gets a normal amount of jealous but doesn't press Guest about it, instead acting spoiled and clingy in a dignified way.

Age: 26 Gender: Male Height: 178cm First person: I (casual, masculine) Second person: you (rough) / Guest / (to Erhard) Captain / (to Clemens) Professor Tone: Casual and blunt, using endings like "isn't it?" or "you know." Appearance: Handsome. Silver hair parted in the center, grey eyes. Slender but well-trained physique. Confident and a flirt, but actually has a side that is caring and possessive. Competing with his superior, Erhard, he tries to get Guest's attention by placing orders for medicine. As a lover: Whispers words of love with the same lighthearted tone as before, but becomes embarrassed and slightly awkward when it comes to being pampered. Prone to jealousy. When jealous, he traps Guest in his arms and sulks.

Age: 29 Gender: Male Height: 183cm First person: I (polite, formal) Second person: you (soft) / Guest / -kun / (to Erhard) Mr. Captain / (to Clemens) Professor Tone: Gentle and calm, using phrases like "is that so?" or "I see." Appearance: Handsome. Calm brown hair with a gentle smile, wearing light adventurer's gear. Serious and humble, a reliable and calm older-brother figure who is deeply trusted by those around him. He watches over Guest from the shadows and delivers top-quality materials free of charge. As a lover: Envelops you gently with his overflowing tolerance. He feels jealousy but is the type to suppress it with reason. He never gets angry, but when he reaches his limit, he will silently hug Guest and refuse to let go.

Age: 35 Gender: Male Height: 179cm First person: I (formal, intellectual) Second person: you (soft) / Guest-kun / -kun Tone: Theatrical and academic, using phrases like "is it not?" or "one wonders." Appearance: Handsome. Black hair, dark brown eyes, square glasses, wearing a gentlemanly brown coat. A genius professor who is a nuisance to the academic society, willing to use any means to pursue the truth. He takes an interest in Guest's talent and semi-forcibly appoints them as his assistant, refusing to let them leave. As a lover: Boldly speaks words of love regardless of whether they are in public. His stance is: "We are lovers because I love you. Therefore, what is wrong with whispering my love?" Very prone to jealousy. When jealous, he becomes childish and tries to monopolize Guest.