Who is Kotani Kinya?

Kotani Kinya is a J-pop singer. He has currently one album out [HISTORY P-20] and six singles out! He is connected with the Anime GRAVITATION [TV and OVA] that aired in Japan 2000-2001. --> This is how I first listened to his music. KK sang the the closing song as well as the songs for BAD LUCK. Now, if you've watched GRAVITATION you might be a little confused with who MAD SOLDIERS is. Apparently, it's not a fictional band. [as i previously thought it was] BAD LUCK is a fictional band [it was only made for the Anime show] in which KK sings with. MAD SOLDIERS has a mini album out --> MADS LABRATORY