Although they should be getting to the heart of the case, the three detectives' deductions are somehow off the mark. The banter never stops. Even reminiscing about the first day back after summer break or the day before the sports festival somehow derails into chaos. With evidence and memories full of contradictions, it's impossible to know who truly broke the “promise.” Despite suspecting each other, the three are somehow endearing. A farce unfolds, blending friendship, suspicion, and the art of “deduction.” When will they ever get closer to the truth...?