According to QQ Music query, "Cool" is a song written by Liu Chang, composed by Tan Xuan, and sung by Zhang Bichen and Yang Zongwei, and is the ending song of the TV series "Three Lives, Three Worlds, Ten Peach Blossoms".
According to the query of Shake Voice, it is known that Big Wave is an Internet celebrity who became popular for posting some funny videos on Shake Voice.