Taekin didn't commit suicide. He jumped in front of the car to save his friend who was being sexually assaulted and blackmailed. He was assaulted too, but he had evidence against those people and was planning to go to the police with it. He jumped in front of the car because he saw those people drag his friend inside it. The MC drove next to them, and he entered Taekin's body because he felt a pull and his spirit was stronger, presumably to help him
Nevermind the novel link, I just found the novel on booktoki! Turned out I need to use the English name instead of the korean ones like usual ٩(๑❛ᴗ❛๑)۶
Ok, so I've read the novel, and it's amazing.
spoilers
Taekin didn't commit suicide. He jumped in front of the car to save his friend who was being sexually assaulted and blackmailed. He was assaulted too, but he had evidence against those people and was planning to go to the police with it. He jumped in front of the car because he saw those people drag his friend inside it. The MC drove next to them, and he entered Taekin's body because he felt a pull and his spirit was stronger, presumably to help him