Si'er used a mirror to support his consciousness, recognized Su Yan as his master, and named himself Su Yan's nickname - Si'er. One day, his master Su Yan cut his wrists and committed suicide for love. Si'er was curious about having the memory of his master and wanted to know why his master committed suicide. Finally, Si'er left, and Si'er accepted the result calmly and discovered his master's love from a unique perspective. Although Si'er is not a human being, she knows that the mirror can not only reflect one side of the world, but also the other side of the world. There is no right or wrong, but only many sides. Even without the illumination of the mirror, many things still have many sides. Looking at the moment one-sidedly, thinking about the results or the future from multiple sides, calm will be timid, rationality will be angry, enthusiasm will be cold, etc. Si'er's master sees too little and leaves early. Si'er sees many sides for her. It is a pity and helpless, and she must accept it before starting over.