Introduction: Best friends, best friends, and lovers in high school are joined by fresh blood in college, breaking all progress... Can Shi Shi, who doesn't like to explain, Ye Yu, who has low self-esteem and sensitive, arrogant Xia Yi, and Yu Fei, who lives with a mask, find their own lives in the confused steps? Happiness; whether the neurotic Yan tide and the low-EQ Gu Mo can pursue their lives as before; can they go on at the pace they imagined, and what will they gain and lose in these accidents... And at the same time, what kind of accidents are still waiting for them. If it happened again, would they want to turn back time and say "Hello, time" to time again?