Mako received his only Oscar nomination for portraying Po-han in The Sand Pebbles.
Po-han is just one of the Chinese who work on the ship until Steve McQueen's machinist Holman takes him under his wing. Mako is fine early on showing a sympathetic face to Holman. He just wants to help Holman unlike some of the other Chinese who like to do things their way. Most of his early scenes make of just small reactions of concern, and surprise while dealing with Holman. Mako is entirely realistic, but really he does not make too much of an impression either.
After Holman brings him under his wing Mako gets some more substantial scenes such as when Holman teaches him to run the ship's engine. Mako again is appropriately realistic, and is actually quite effective in showing Po-han's learning. He also has a low key charm in his performance that does make Po-han endearing in his own small way. This is still not incredible work by Mako but it is absolutely solid since it fulfills the role completely.
Mako continues his portrayal in the same fashion as Po-han boxes one of the racist men on the ship. He is again good, properly realistic, and we can easily sympathize with him through Mako's likable portrayal. Again it is not a whole lot but it also is all that the film asks of him. Po-han is not a tremendous role, but Mako really is perfect in the role.
He does his very best to be a character not just a stereotype as he easily could have been, and we most certainly feel for him all too well in his final scene. It is a good supporting performance not the best in the film, and certainly not the most memorable. After all Mako gets cut off just as his character is really becoming interesting, nevertheless Mako does absolutely fulfill his role, and deserves credit for doing so.