Masira is a human with ape-like features, he wears an orange-yellow jumpsuit, and also has headphones and goggles. What makes him interesting is he apparently has a tail, although sometimes it cannot be seen. An example of when it clearly can be seen is when Bellamy first tackles him from behind, during the Bellamy Pirates vs. Saruyama Alliance fight, or when he is carrying wood to fix the Going Merry. Masira also has huge arms and some kind of piercing around his wrists.
After the timeskip he no longer wears the jumpsuit, but has a shirt with the same design on the front. Other than this he looks the same as before.
Masira often acts very serious, but is very silly and not very bright in reality. He is easily angered, notably most of all, by the idea of someone stealing his salvage operations, yet at the same time has a rather friendly disposition, especially if someone shows interest in his salvaging skills (putting a lot of effort to impress observers) or calls him a monkey. He is easily won over with friendship along with his brother when the Straw Hats appear at their home on Jaya Island.
Like his brother, he is protective of Cricket who they have come to know as a father figure. He and his fellow Alliance members displayed a amazing spirit to get back up and continue their modifications to the Going Merry after Bellamy's attacks. On their last encounter with the Straw Hats, all sides left on good terms.
Masira is immensely strong, being capable of knocking out a gigantic eel with merely a punch while underwater.
Masira also has amazing lung capacity as he was able to blow up a giant balloon in nearly a single breath. He is also an excellent diver and has great knowledge of how to recover shipwrecks from the sea bottom, befitting his epithet as "Salvage King".
Saru Naguri (猿殴り,Saru Naguri?, "Monkey Punch"): Masira winds up and delivers a punch powerful enough to fend off a giant eel.
Saru Lunge (猿ランジ,Saru Lunge?, "Monkey Lunge"): An anime only attack, both he and Shoujo launch a strong punch against their opponents. This was first used against the Bellamy Pirates. In the Funimation dub it is called Monkey Punch.
Masira first appears during the Jaya Arc, after a huge ship fell from the sky and into the ocean, and it is here where he first meets the Straw Hats. However, a sea monster and "giants" appearing in the ocean interrupt them. Somehow as the Straw Hats attempt to escape he winds up on the Going Merry and is quickly kicked off.
After the Straw Hats meet Cricket, Masira and Shoujou (whom they run into a while later) act a bit more friendly towards them and help modify the Going Merry so it can travel to Skypiea.
When Luffy successfully rang the Shandorian Golden Belfry Bell, it brought the Alliances' dream to fruition, and proved that Skypiea does exist. Masira and Shoujou then decide to follow Cricket to pursue their next dream.