Sexual Judgment - Part 1

Story

At Seiryu Academy, which Masayoshi Negishi attends, the teacher Yuko Ayase, who had earned the trust of the students, met a mysterious death by falling. It was processed as an accidental death caused by leaning on an old wire fence on the rooftop, which was supposed to be off-limits, but four students who were indebted to Yuko couldn't accept it and set out to investigate the cause of her death. Masayoshi lives alone with his stepsister Kizuna, leading ordinary days. Masayoshi is the child of a criminal, raised as if he were his own son by his stepfather, who was a detective. He has no blood ties to his stepsister Kizuna, but Kizuna doesn't know this. Now that both his stepfather and stepmother have died, the death of Yuko, who had looked after him like a mother, was a great shock to Masayoshi and Kizuna. After Yuko's funeral, Masayoshi receives Yuko's keepsake notebook. In the notebook are the names of several female students and a schedule from just before her death. No names are written, but it says 'after school, consultation.' 'It was the same when it was our turn, but Ms. Yuko used to give counsel to students with problems... In other words, there's a chance that among the names in this memo is the cause of the teacher's death, or the one who left her to die.' The four exchange information in the photography club's clubroom after school.