This spring of 2023, young men and women have gathered again for the 4th season of Heart Signal. Yoon Jong-shin, Lee Sang-min, Kim Ea-na, Kang Seung-yoon, Mimi, and Kim Chong-ki join as panelists. Heart Signal 4 finally begins, and 6 occupants are revealed. What are the heart signals that were sent on the first day that will make your heart flutter? Meanwhile, someone’s word turns the place into a battlefield. Will there be a storm at the Signal House?