Junpei Shibayama is a main character in the Digimon anime series Digimon Frontier. In this series, a group of chosen human children were given the ability to turn into Digimon.
J.P. is the oldest member of the group, and was the one who was chosen to wield the "Spirits of Thunder". This allows J.P. to use AncientBeetlemon's power to turn into two Digimon forms which use mainly electricity attacks.
At the start of the series, J.P. shows some jealousy towards Takuya Kanbara, the main character of this series for being Tommy Himi's hero and being able to combine both of his Digimon forms into a more powerful form. He also shows feelings for Zoe Orimoto, the only female of the group. J.P. also seems to have a hidden fear of being alone - despite being constantly surrounded by people when he was in the real world, he felt that he had never really been anyone's real friend.
This fear spawned some rather obnoxious behaviour in the earlier parts of the series. As the series progresses, J.P. learns to confront his fears, and begins to see the other members of the group as real friends. He also overcomes the jealousy he feels towards Takuya.
He's the first one to kill one of the evil Legendary Warriors: after Grumblemon lost his Beast Spirit to Takuya as BurningGreymon, Grumblemon ambushes the Digidestined with a bunch of Golemon. After Whamon saves him from Grumblemon's attack, J.P. finally gets his Beast Spirit which was in Whamon's stomach and evolves into an out of control MetalKabuterimon. He gains control over himself quickly and shoots Grumblemon, killing him, allowing J.P. to take his Human Spirit and give Zoe back hers.