At first sight, they are parallel lines that do not touch each other; at second glance, they are half-acquainted people who have a great time chatting on the Internet. I won't leave you behind, it's what you said and what I want to say. Three years is your promise to me. It is a sentimental expression when I was young. However, it cannot be said in the face of time, and it cannot escape the present after all. Dugua and Eryu, long time no see.