Unaired episode 13 included with the fifth Blu-ray and DVD volume.

Just who is Sakamoto? He's enigmatic. He's clever. He's dashing. No challenge is too great and no cause is too small for Sakamoto. Girls love him, guys hate him for it, and despite efforts to humiliate him, Sakamoto is flawlessly able to emerge from the fray, even cooler than ever. Who knows what Sakamoto is going to do next? Whatever it is, it will be fabulous!

(Source: Crunchyroll)