As the Guardian Mage called out their names one by one, each person stepped forward to receive the cursed seal. This seal required a contract to take effect, so it could not bind an unwilling recipient. Nor could the Daimyo demand that Asuna and the others accept excessively unreasonable terms.
The contract stipulated three points between the Daimyo and the Guardian Ninja: first, they could not harm the Daimyo; second, they had to obey the Daimyo's orders to use force as a demonstration of loyalty; third, the Daimyo could not demand that the Guardian Ninja reveal their personal secrets.
The first two provisions ensured the Daimyo's safety and their loyalty, while the last prevented him from using the contract to pry into the Guardian Ninja's secrets. This was their mutual agreement. The Daimyo understood that the Guardian Ninja from Konoha would not necessarily submit to him in earnest and would certainly act in secret. He would not push them too hard; some leniency was necessary.
Once bound by the cursed seal, any Guardian Ninja who attempted to violate the contract would suffer intense pain. It would not kill them, but the pain would leave them barely able to move.
The Guardian Mage inscribed the cursed seal on everyone, nodded to the Daimyo, and stepped aside. Another person then came forward and gave each of them a sash bearing the character for "fire." This was the identifying emblem of the Guardian Ninja. As the Daimyo's personal guards, they enjoyed exceptionally high status and prestige.
Everyone accepted a sash and fastened it around their waist. Looking at the ninja before him, all now bearing the Guardian Ninja emblem, the Daimyo nodded in satisfaction. Although he knew some of them were not on his side, he could not suppress his sense of gratification.