Use your breasts.

His back, that was always afar, now, this close...

In case anyone didn't get this cultural note, being broad-shouldered is considered one of the finer points of masculinity to the Japanese eye.

For Hinata's case, she's been watching him from behind for almost his entire life, and has seen him go from the skinny runt he was as a kid to the broad-backed man he is now.

Flashback time!