Chōsokabe Motochika from Sengoku Basara! :P
Sadly didn't find a tag for it from Otaku Category list :(
Title comes from the game and anime, the crewmembers will cheer and refer Motochika as Aniki aka Big Bro!

Chōsokabe Motochika is a real historical figure from 1500-1600 era Japan.

Done with watercolors, my wild guess, I don't know really. They probably have a cool techinal term instead of plain watercolors. Dig them from a dusty box.
Touch up with Photoshop to get the colors more out after scanning.

Chōsokabe Motochika, Sengoku Basara (c)Capcom.
Art(c)Tien-kun, 2011.