From Bulbapedia, the community-driven Pokémon encyclopedia.
Nihei (Japanese: ニヘイ Nihei) is a recurring character in the Pokémon anime who made his first appearance in person in The Legend of the Ninja Hero!. He is the younger brother of Ippei and the older brother of Sanpei and hails from Ninja Village. Nihei is the second strongest of the village, only behind Ippei.
Nihei was first mentioned by Sanpei in A Rush of Ninja Wisdom!, and was seen only in a fantasy.
Nihei made his first physical appearance in The Legend of the Ninja Hero!, where he was making preparations for the festival. He then welcomed Sanpei, when he returned to the village, accompanied by Ash and his his friends. He then had Pokémon battle with Sanpei and managed to win rather easily.
Later, he and Ippei met Sanpei, Ash and his friends in the temple dedicated to the village's heroes, where Ippei told them about the legend of the Pokémon that had protected the village once, when a battle between ninjas took place, and showed them the leader of the heroes, a Greninja.
When the village got attacked by a ninja army, Nihei and Ippei sent Sanpei, went to face them. After discovering that Hanzo, the village's chief, had been captured, Nihei joined the others to hear Saizo tell about Kagetomo. After discovering Hanzo's location, Otori Mountain, everyone decide to head there and save him.
Upon arriving at Otori Mountain, the group got attacked by Heidayu and the ninja army. Nihei used his Venusaur to battle the ninja army, alongside Serena, Clemont and Shinobu. They eventually managed beat them, while Ippei defeated Kagetomo and saved Hanzo.
The day after the village's festival, Nihei said goodbye to Ash and his friends. After their departure he informed Ippei and Hanzo about the mysterious power of Ash's Greninja he had witnessed.
This is listing of Nihei's Pokémon in anime.
- The names of Ippei, Nihei and Sanpei are a play on the Japanese words for one, two, and three: "ichi" (一), "ni" (二) and "san" (三).