Quick sketch version in Photoshop (reminds me never to draw in that again), might redo this, might not... anyway, moving on! This is just one sequence of events, it varies by story, picture, etc.

Age five: Kira keeps his hair long at this point. Blue the octopus is still around.

Age thirteen: Hair forcibly cut, bell made to be warn, and Blue the octopus taken from him. He becomes impossible to control, dark side emerges.

Age seventeen: Free again, happy, carefree, letting his hair grow out once more. Childlike, having never grown up.

Age twenty-five: Neat and tidy, keeping himself clean and working. Decidedly removing his bell to show his independence. He likes to be shirtless still, but his boss won't let him.

Any age you'd like to see more of?