The Night Before the Second Exam

is episode 398 of the Naruto: Shippūden anime.

Summary
After learning the nature of the test, Neji devises using wall vibrations to contact Lee and Temari of how to answer. Everyone else soon follow, despite Neji having a confrontation with Sajin. Once genin finish their written tests, Shikamaru presents a second question where each team must name someone in their group who they would sacrifice in a situation that requires a decoy. He adds the decision must be unanimous among each team and that the selected would be disqualified. Meanwhile, after Homura and Koharu relay a warning from Danzō to be wary of the Rain genin, Tsunade becomes more suspicious when Kankuro informs the Hokage that they will look after their Sand genin during the second phase. Back in the test rooms, Neji saw through Shikamaru's trick and left it blank. This act allows Team Guy to pass alongside Team Kurenai, and the team of Sakura, Ino, and Choji when they reached the same conclusion. Sajin and his team are among those eliminated due to choosing Mijin as the decoy. Neji explaining to him that the trick question was to test a team's loyalty towards its members. Temari informs the remaining teams that they are to race to the Hidden Sand Village with the ten teams able to participate in the second phase of the Chunin Exams.