One of the first times we meet Boruto, he’s being shamed during a final round of the Chunin Exams. But why did Boruto fail the Chunin Exam?
Boruto had to fail the Chunin Exam because he used a scientific ninja tool. Naruto banned the use of scientific ninja tools during the exam, as he felt it defeated the purpose of nurturing new shinobi.
He was forgiven for cheating during the exam after helping save Naruto from Momoshiki.
Plot Behind How Boruto Had to Fail The Chunin Exam
In chapter #2, Sasuke agreed to take Boruto on as his student if he could create a Rasengan.
He was able to create a small, not impressive Rasengan. Boruto walked home shamefully, feeling deflated and looking for any way to impress his father and master. Katasuke Tōno, a researcher who specializes in scientific ninja tools, approaches Boruto.
The researcher shows Boruto his testing laboratory of scientific ninja tools. He says that the way of Boruto’s ninja generation should be that of “using little effort to procure exceedingly large results.”
He gives a ninja tool wrist device to Boruto, who brings it home. Boruto then uses the powers of the ninja tool to “master” the Rasengan in only one day, Sasuke in turn agreeing to make Boruto his student.
The Chunin Exams approach and Boruto, alongside his team, are able to pass the first few rounds easily. Boruto uses his ninja tool during a “capture the pennant” activity, drawing some suspicion from onlookers.
Next up was the 1 on 1 battles. Boruto’s easy win over Shikamaru’s son, Shikadai, turns to accusation once Naruto successfully notices a ninja tool in use. Naruto dropped down into the arena and lifted Boruto’s sleeve, revealing the ninja tool.
I banned the use of scientific ninja tools in this exam. Because using these instead of your own chakra defeats the chunin exam’s purpose of nurturing new shinobi.
Naruto to Boruto | Chapter #5
Naruto then motioned to proctor Lee that Boruto was disqualified. He then changes the winner to Shikadai, and Naruto removes his son’s Genin headband and declares him no longer worthy of being a ninja.
So that’s the answer. Boruto was forced to fail the Chunin Exam because he was cheating, using a scientific ninja tool.