Kasaki Heizou was the 3rd seat of the 9th Division in the Gotei 13 and served under his Captain Muguruma Kensei.

Kasaki is a tall and muscular Shinigami. He is bald but has a mustache. He usually has a serious look on his face and dresses like the other members of the 9th Division, with the standard Shinigami uniform and a white jacket that he wears over his Shinigami uniform with a collar that reaches up to his neck.

Turn Back the Pendulum arc:

Kasaki was first introduced when Muguruma Kensei and other seated officers of the 9th Division were sent to investigate the disappearance of the Rukongai residents. He and the other 9th Division members were seen saving a young Hisagi Shuuhei and his friends from a Hollow. When Kuna Mashiro (who was absent during the fight) discovered 10 empty shihakushou nearby the Hollow attack site, Kensei realizes that it matched the same number of a vanguard that was sent to investigate earlier. Seeing how the case had become more serious now that Shinigami were missing, Kensei gave his men various orders. Determined to stop the culprits before they reach Seireitei, Kensei tasked Kasaki with having the rest of the unit, which was on stand-by, to bring a tent and set up camp. Later in the night, Kasaki was shown to be with his captain and lieutenant, resting while the other seated officers stood outside on guard duty. Kensei and Kasaki then rushed out of the tent as they heard the screams of the officers outside. The two drew their swords upon seeing the corpses of their fellow Shinigami, but were promptly attacked. Kasaki was killed and Kensei was grievously injured.

Swordsmanship Specialist: As a 3rd seat officer of the Gotei 13, he possesses skills in the use of swords during combat and knowledge of swordsmanship.

Shikai: Not Revealed

Bankai: Not Achieved

(Source: bleach.wikia.com/wiki/Heizō_Kasaki)