1, it doesn't matter whether it is the crown prince or not. Because the broken era was the "Muromachi shogunate" era in Japan, at that time the emperor was already a puppet, and General Ashikaga Yoshimitsu was the strongest general in this shogunate period.

2. However, in other words, according to the understanding of animation, Yixiu is a prince. According to the ancient Japanese system, children of the royal family, generals and famous artists who have the right to inherit but are not the eldest son generally choose to become monks. The most famous is Shangshan Chinobo (referring to heaven and earth, the Japanese Warring States God of War). When he was young, Kenshin was sent to be a monk because he was the last son. This is a radical way to prevent family disputes. There is also a cartoon (distant time and space 1), in which Yongquan is the king and takes a family to practice.