Shun is a shinobi from Konohagakure who saw action during the Fourth Shinobi World War. He was stationed in the Second Division under Kitsuchi and got deployed alongside Neji Hyūga and Natsu to reinforce Naruto, Killer B, Kakashi, and Guy on the battlefield.
On the way there, Shun picked up on some troubling intel and made sure to fill his team in—apparently the real Madara Uchiha had actually shown up to fight. When enemy forces attacked their group, he and Natsu managed to take down a couple of opponents with help from Neji, though the two of them butted heads afterward. Neji had to step in and remind them both to stay focused since they were heading into the thick of it.
Anime Debut: Naruto Shippuuden Episode #330
Content compiled by AnimeList.moe from publicly available sources.