Mannen and Shin are two of the seven Leafe Knights who serve the Prétear, and they belong to the younger trio of the group. Mannen holds the title of Knight of Ice, while Shin is the Knight of Plants. Sixteen years before the events of the story, both of them, along with their companion Hajime, died while fighting the original Princess of Disaster and were subsequently reborn as children. This shared past binds them closely and informs their present-day personalities and actions. Mannen is the self-appointed leader of the three youngest knights. At ten years old, he possesses a natural inclination to take charge and is brimming with confidence, courage, and a strong desire to be seen as mature and capable by the older knights. He often devises clever plans to help the group, such as using Shin as bait to locate the Prétear, though such schemes frequently draw criticism from the older knights, particularly Goh. His eagerness to prove himself can lead him to rush into battles before the others, which sometimes creates problems. While he tends to boss around and tease Shin and Hajime, calling Shin a baby when he cries, Mannen is deeply loyal and protective of them. He regards Himeno, the Prétear, as an older sister figure and is determined to shield her from harm, a sentiment he expresses even in his sleep. His brash exterior masks a genuine need for respect and a longing to be treated fairly by the senior members of the group.

Shin is the youngest of all the Leafe Knights and is notable for his gentle, quiet, and sensitive nature. He is often described as a crybaby but possesses a fundamentally bright and mild-mannered disposition. As the Knight of Plants, Shin has a special connection to plant life, enabling him to sense the state of plants and understand their feelings. He is deeply affected when plants are harmed and uses his abilities to create barriers and seal away demon larvae, as well as casting a spell called Beyondios to create a separate dimension for battles to prevent harm to the surrounding environment. Shin looks up to Mannen as a model, often following his lead alongside Hajime. The trio is almost inseparable, though Shin sometimes bears the brunt of Mannen's bossiness. He is also sensitive to the emotions of others and responds to kindness with trust, forming a strong bond with Himeno, who treats him with care and gentleness. In the anime, Shin does not merge, or pret, with Himeno, but in the manga he does, which leads to him expending all his power and disappearing before being revived by the White Prétear's power at the climax. His ability to manipulate plants and create protective fields provides crucial support in the knights' battles, even though he is not directly involved in offensive fusion attacks in the anime. Together, Mannen and Shin represent the younger, more vulnerable aspect of the Leafe Knights. They remind the group of what was lost and reborn, and their development centers on growing from impulsive children into dependable allies who contribute meaningfully to the fight against the Princess of Disaster.