Juhino kidnapped herself, to give Kellban his alibi. She traded a piece of stationery paper from Ildsina for the promise that she would purposely miss the exam and let Ildsina take first. When Ildsina found out about the kidnapping, she clammed up to avoid being implicated too. The kirin that Kellban bought, plus the agriculture study Juhino had been doing, was because they were planning to move out to an abandoned farm far out on the shell and live together, basically eloping. Juhino picked up the ransom herself, and gave it to Crisul, a nice guy in her neighbourhood who had promised to swear off gambling, but who otherwise has no involvement in the crime.

Naming either Kellban or Ildsina as the culprit will net a technical "win" in the case, and naming both of them will be the "correct" answer, since all three including Juhino herself participated in the kidnapping. Naming Crisul as the suspect will be considered a "fail" of the case, since he was only involved after the fact due to the ransom.