<Let's Go!> is the fourth illustrated book in the ‘Youth Global Citizenship Education Project’ jointly published by Gwangsan-gu Office of Gwangju and Honam University. With the theme of mental health, the main character 'Yuri' shares various emotions in 'Emotional Train', It's the process of confronting her candid feelings of her own while seeing people who receive her empathy and comfort. By using 'Wi-Fi' and 'flowers' as devices to express emotions, anyone can easily immerse themselves in the story.