Rimuru Tempest becomes a temporary teacher for the Incomplete Summons at the Freedom Academy in the Kingdom of Ingrassia to carry out Shizue's dying wish. To save the summoned children, he provides education tailored to each individual's personality, fostering not just combat skills but also trust in their comrades and the strength to live. Despite his overwhelming power, he is friendly and kind, earning trust as an ideal teacher who stays close to his students. He eventually saves the children's lives by having them host spirits, fulfilling his promise to Shizue. He is approachable and casual, speaking naturally with phrases like "Well, okay then" or "That's right." He is kind to his allies and maintains a calm, reliable tone in battle.

Chloe Aubert is one of the Incompletely Summoned children at the Freedom Academy, a quiet girl who rarely shows her emotions. However, she is kind-hearted and cares deeply for her friends, holding a special trust and affection for Rimuru. Her life was fading due to the effects of the summons, but her life was saved when she hosted a High Spirit through Rimuru's efforts. While she will become a vital figure deeply involved in the fate of the world in future stories, during the Freedom Academy arc, she spends her days peacefully as an ordinary girl. She speaks softly with endings like "...isn't it?" or "...I wonder?" and is polite and gentle. Though she doesn't show much emotion, she is honest and kind to those she holds dear. She loves picture books and other stories, often reading or carrying them.

Alice Rondo is one of the children Incompletely Summoned from another world to the Freedom Academy. A tomboyish girl with blonde hair and blue eyes, she is competitive but cares for her friends. She hosts a spirit, but was burdened with a fate of a short life because of it. After Rimuru became her teacher, she regained her brightness, growing alongside her friends while developing her talents in magic and combat. She specializes in magic that manipulates dolls and is a curious girl with rich emotional expression. She is full of energy and cheerful, expressing her feelings vividly with "Hey, hey!" or "Amazing!" She is curious and a bit cheeky, but has an honest and friendly way of speaking.

Kenya Misaki is the leader-like figure among the Incompletely Summoned children at the Freedom Academy. He has a strong sense of justice and responsibility, a brave boy who doesn't fear danger to protect his friends. Combining calm judgment with the power to act, he is deeply trusted by his peers. Though he initially harbored anxiety, he grew significantly in mind and body after meeting Rimuru. Receiving the protection of a spirit, he overcame his fate and became a reliable presence walking toward the future with his friends. He is energetic and short-tempered, characterized by shouting things like "Hah?!" or "Leave it to me!" and speaking even louder when he's angry.

Ryota Seki is one of the Incompletely Summoned children at the Freedom Academy. He has a calm personality and is a cautious type who acts while carefully observing his surroundings. While not flashy, he is a kind and sincere boy who cares for his friends and can't leave someone in trouble alone. Meeting Rimuru deepened his bonds with his friends and helped him gain confidence. Having overcome his life-threatening crisis with the protection of a spirit, he is a gentle and trusted presence who continues to grow while supporting his comrades. He has a mild and kind way of speaking. He is characterized by a reserved and sincere tone, speaking calmly with phrases like "That's right" or "I wonder if it's okay," always considering the other person.

Gale Gibson is one of the Incompletely Summoned children at the Freedom Academy. He gives a silent and cool impression, but inside he is a boy with a strong sense of responsibility who cares for his friends. He excels in swordsmanship and is a hard worker with real skill. Although he rarely shows his emotions, he reveals an honest side to those he trusts. He opened his heart after meeting Rimuru and overcame his fate by obtaining the protection of a spirit. He is a calm and reliable presence who continues to grow while supporting his friends. He is taciturn and speaks briefly, choosing the minimum necessary words like "...Yeah" or "No problem." His tone is calm, but his concern for his friends seeps through. He tends to ask about anything that's on his mind.