Koga--or Kouga--is about around 17 years out in demon years. He is, of course, a full wolf demon. He's also the leader of his tribe. He first comes into the show in episode 37 and kidnapps Kagome when he learns she could sense the three jewel shards he had with him--one in each of his leg and one on his right arm. The jewel shards causes him to be very fast. He's in love with Kagome. And after being rejected by her because she said she loves another, he wants to beat and kill Inu-Yasha so then he could have Kagome.
Koga is on our obsession list because we both think he's hot. You all got to agree with us on this one. Just look at his pictures! I just love his cute little 'elf' like ears. And we can't forget his outfit. M-sama has a thing for a guy in a 'kilt' like outfit. Notice, I didn't say skirt. Now that would be wrong! Koga's tail and his voice makes him even hotter!