kookoo-sei? as in high school student? (forgot XD)
er... watashi wa TK desu. Watashi wa jyuurokusai. Hajimemashite. Yoroshiku. O genki desu ka?
watashi wa = i am / i
TK = my name..so put your pen/nick name there
desu = just an ender word. Easiest way is to think of it as a full stop to back up a statement?
Jyuu = 10
Roku = 6 (10 + 6 = 16)
Sai = years old / age
Hajimemashite = Nice to meet you
Yoroshiku = slang/lazy way saying "doozo yoroshiku" or "Yoroshiku onegai shimasu." which means
"I hope you will take care of ( someone / something ) in a way that is convenient for both you and me. (I count on your cooperation.)"
"Please be kind to me."
O genki desu ka? = how are ya? / how is life? (the "ka" makes it a question)