Sasaki is one of the Tobiroppo, the strongest six Shinuchi of the Beasts Pirates, and leader of the crew's Armored Division. Prior to joining the Beasts Pirates, he was captain of his own crew. Due to his actions and role, he is a supporting antagonist in the Wano Country Arc. Sasaki is a very tall man at just shy of 3.2 meters, with a portly build and light skin. He possesses sharp and slanted, blue eyes underlined by notable creases, a mildly hooked nose, and a fang-filled mouth with notably oversized bottom canines (jutting out even with his mouth closed), as well as a flat chin. His shaggy hair is colored yellowish-green and reaches down to his middle back, with a golden hoop earring visible on both his ears. A dark tattoo is located around his shoulder areas, including the upper arms, chest, and back, with many curved, vane-like shapes bringing on a resemblance to wings.
As for clothes, Sasaki's seem a distinct blend of traditional Japanese and attire associated with a soldier or dictator. On his head is a military-style cap with a black, low-set visor. Its white crown is extra-wide and puffy, dented breadthwise with the front raised, and split by a lengthwise seam. Above the black bottom edge (spaced from it) runs a black band lined with a row of gold studs, holding in the front a golden badge depicting a double-cross shape (eight-armed, the diagonals less prominent, with a small middle stud). Set below, front and center, is a pair of slender, golden horns that curve upward, lending Sasaki (together with his fangs) a rather demonic look. Otherwise, the man wears a cloak akin to a seaman's, slung on his shoulders with the sleeves hanging back, that has a folded standup collar bearing on each side a simpler version of the hat's badge. The coat has a solid-white coloration over its upper half, which ends around waist level with a downward-facing flame motif, contrasting against the dark-colored rest of the coat. Below, Sasaki's torso is bare, partly showing off the aforesaid tattoo. For lower wear, Sasaki dons a hakama-like article resembling the bottom half of a double-breasted trench coat, which is flame-patterned the same as the cloak, closed by eight buttons, and held up by a plain dark, buckled belt. Finally, Sasaki sports a pair of dark gloves and double-toothed geta sandals. Sasaki is shown to be a relatively calm and easygoing man, yet also prone to derision, not above teasing even those of equal rank scoffingly. Still, he acts rather cordial toward those he considers friends, such as formerly "Kyoshiro", but will not tolerate any breach of fidelity; if betrayed, he will aim to ensure the traitor pays a steep price. It is also implied by Kyoshiro that Sasaki is fond of partying, since the former thought Sasaki's presence outside the Golden Kagura was uncharacteristic of him, and he conducted his search for Yamato with a sake bottle in hand, further seeming fond of drinking.
Rather ambitious, Sasaki seeks to become one of the Beasts Pirates' All-Stars by claiming a spot from the current ones, causing him to disregard their senior authority. This resolve, according to King, arises from Sasaki's past as a captain of his own crew, and also bears out on his part a high degree of confidence in his own strength, enough for him to look forward to gaining chance to directly challenge an All-Star. In combat, Sasaki is similarly self-assured, especially due to his ability to become a dinosaur, believing dinosaurs to be the strongest beasts to have ever existed. Like the other Tobiroppo, Sasaki seems to heavily respect Kaido. When Ulti insulted their boss in his absence, Sasaki nonetheless grew shocked. He also seems to be on casual enough terms with Kaido to express his wish to drink with him during the Golden Kagura, stating to have no interest in fraternizing with mere underlings. On the other hand, Sasaki (like Who's Who) looks at the current All-Stars foremostly as obstacles in his pursuit to take one of their spots, thus acting insubordinate toward them and ignoring any summons order without Kaido's name attached to it. Further, whilst friendly enough with his fellow Tobiroppo to sit and banter with them, Sasaki views them as competition, given that some of them too aspire to climb up a rank. He mockingly discouraged X Drake and Page One from pursuing such advancement, effectively calling the latter dead weight. Sasaki claims to have seen a friend in Denjiro during the latter's time posing as Kyoshiro, though with Denjiro's backstabbing him during the latest Fire Festival, Sasaki took to swearing he would avenge himself on the samurai. As one of the Tobiroppo, Sasaki holds great authority in the Beasts Pirates, only Kaido himself and the All-Stars ranked above him. In particular, Sasaki seems to lead the crew's Armored Division. Also, as an ex-pirate captain, Sasaki used to have full command over his own crew at some point. Combat-wise, Sasaki can be assumed to be formidable as one of the strongest six Shinuchi, potentially worth challenging the All-Stars for their post (something Sasaki seems confident in his ability to do).
