Agile fire and explosive user, Renkotsu is the second in command and one of the more intelligent members of the Shichi'nintai. He respects his leader just as much as any other member of the Shichi'nintai. However, with the corrupt power of the shard of the Shikon Jewel embedded in his neck, he starts to feel hatred and jealousy towards his leader and vows never to die again because of him by any means necessary. To do this, he requires possession of all the Shikon Shards Naraku gave them.

Renkotsu is first of the Shichi'nintai to find out some truth about Naraku and reasons that Naraku is not to be trusted. He finally comes to the point where he believes he is better than the others and eventually becomes a little overconfident. After taking Jakotsu's shard (who was defeated by InuYasha) and killing him, Renkotsu tries to kill Bankotsu, who has found out about Jakotsu after an insect brought him Jakotsu's hairpin. He fails, and Bankotsu takes Renkotsu's jewel shards, killing him, and leaving Bankotsu the last of the Shichi'nintai. In the anime he actually lived just a little longer than in the manga, being told to fight first by Bankotsu before he was killed by him.

He is an expert with explosives and metallurgy who used bombs, cannons, and other artillery; created fire from his mouth by drinking a liquid from a calabash bottle and alternatively from what seems to be a crude form of flamethrower; set wires hooked onto his hands on fire, thus pulling his victims into a net of fire. He was also a gifted strategist, and possessed some skill at hand to hand combat although the only member of the group he surpassed in fighting skills was Mukotsu. He was also skilled at mechanical work, to the point of being able to reconstruct Ginkotsu into a living artillery weapon resembling a modern tank. His only weakness is the fact that he needs to carry around his contraptions which could affect his mobility.