El guardaespaldas de Honeko Akabane, 4

The third-year students of Sôsôji High School are, in reality, Honeko Akabane's bodyguards, and Arakuni Ibuki has joined them to catch the traitor hiding among their ranks. After experiencing the bitter taste of defeat on the school trip, the members of Unit 3-D plead with their former teacher for help in improving. Meanwhile, the term exams are fast approaching, and to make matters worse, the group's traitor, Kuran Shutô, wants to remove Ibuki from his position as a bodyguard.