When he was young Tobirama paid little attention to the dots of color on his face. They didn 't hurt or impede his fun in any way and lots of the adults around him had some sort of color on their skin too. If it wasn 't unusual he didn 't see a point in worrying over it and if he wasn 't worrying about it then he didn 't see a point in asking many questions. The dots spread out across his face so gradually he hardly noticed until one day he looked in the mirror and saw lines instead.

He went, of course, to the one person he knew he could trust with any question.

'They 're part of your soul mark, ' Hashirama told him. 'Everyone has something. See? Here 's mine! ' His brother kicked off one shoe and pulled down his stocking to show off the splash of green painted along the bottom of his foot, something Tobirama had seen many times before yet never thought to question.

'But they 're getting bigger. '

'Yeah, of course, that 's what they do! '