Why did Jadoo kill Oma Kokichi during the day?

Because they are playing a killing game, and Oma Kokichi is full of lies.

He threatened everyone's life, seduced everyone for the purpose of saving them, and coerced Baitian to agree to his plan. So Oma Kokichi, with his lies and jokes, lay on the platform of punch. The two dying men began their last conversation. Two people will never understand each other, but it is these two people who do what the other party is most used to and despised. Then, after the unforgettable pain, Oma Kokichi disappeared from this world, leaving only his endless scams and unsolved lies.

Introduction to the third desperate article: Private Peak Hope College, a privileged college recognized by the government, was established to train super-class high school students in various fields. In this college, there are two disciplines, namely "undergraduate" with talents beyond the college level and "preparatory discipline" that anyone can enter as long as they pay high tuition fees. The class of 77 undergraduates are not only brilliant, but also full of personality. They not only insist on their own talents, but also understand that "the important thing in life is not talent, but to sharpen their personality and create memories in communication with others", and they all eulogize the life in the academy like ordinary high school students. However, due to mysterious projects, academic differences caused by academies are rampant. Hinata Hajime, a teenager who is eager for talent and belongs to the preparatory discipline, met his own destiny and led the college and the future in an unpredictable direction. This is the story before "the biggest and most vicious desperate event in human history". A hopeful story that ends in despair.