Tessai is a very tall man who is covered in muscles that Rukia describes as being like granite. He has an odd hair style that looks like it is the results of his going partially bald. His hair, what is left from the back of his head down, is pulled into tight rows of braids. Tessai also has a mustache that runs back and connects with his sideburns and connects from there with the rest of his hair. He wears rectangular glasses that look small for his face. Tessai's usual clothing appearance is a white t- shirt plain pants, and an apron over his clothes.
Tessai is a loyal man who stands firmly behind Urahara and works diligently to perform as best he can. Tessai is a rather polite man who does he best to keep Ururu and Jinta in line at the shop, usually having more problems with Jinta than Ururu though.
When Rukia comes to the shop to get her order and her Mod Soul dispenser Tessai is hard at work at the story early in the day. Tessai doesn't get to o involved in this story other then by making a few appearances and pointing out to Kisuke that they will have some trouble on their hands if Kon isn't apprehended and destroyed.
Quincy Archer Hates You and Battle of the Rubicon
When Rukia comes back to the Urahara Shoten shop she walks in on Tessai reprimanding Jinta for picking on Uruuru outside the shop. Rukia makes the mistake of trying to kick Tessai in the rear, to which she remakes is like kicking granite. Tessai brings Rukia in to see Kisuke and reveals that he is at least over two hundred years old when she brings up Quincies. Tessai remarks that the name brings back memories and that it has been over two hundred years since he has heard of them.
When Rukia's Hollow alert goes off Tessai and the rest of the shop get in gear and load up to help kill off the Hollows, but not before Kisuke and them do some meddling by gathering Sado and Orihime. When Ichigo and Uryu decide to help each other Tessai and the gang attack the Hollows. Tessai displays incredible strength as he punches through a Hollow's head and mask with a palm punch.
After the battle is over Tessai and the kids begin their clean up duties.
Death Trilogy Overture and Broken Coda.
After Ichigo is decimated by Byakuya Tessai and Urahara retrieve and nurse him back to health, Tessai actually lays on him to keep a better watch on his progress. When Ichigo returns that night to begin his training he find an underground bunker that Tessai and the others made that stretches several city blocks in every direction. As Ichigo begins his training Tessai helps to make sure that he doesn't get killed before he regains his powers. After Ichigo's first lesson Tessai cuts his Chain of Fate and follows him down into the Shattered shaft so he can seal his arms using a Kido. Tessai demonstrates his ability to control Kido by casting the spell without using any words and maintaining the Kido with his hand motion only.
The Blade and Me
When Ichigo doesn't manage to get free from the Shattered Shaft quick enough Tessai attempts to seal him in the pit using a level 99 that has three phases. Tessai does the incantations flawlessly but Ichigo's spirit pressure saves him by destroying the incantations. After Ichigo and Urahara begin the final lesson Tessai crawls out of the pit and complains only about his glasses being broken.
When Ichigo and Kisuke begin using their Zanpaku- tos Tessai takes cover with the kids and stays in position to cover them in case anything should happen.
After Ichigo finishes his training with Kisuke Tessai and the others help to get ready for the teams adventure into the Soul Society. When that day comes Tessai is delighted and touched by Orihime's adoration of the underground bunker.
When Ichigo and the others return home from the Soul Society Tessai and the that team welcome them by catching them as they spill out the passageway. Tessai contributes by catching the bundle that Ururu gathers them into before Jinta can clobber them using his over sized metal club.
Powers and Abilities
Tessai shows an incredible amount of strength several times in the series. Taking a kick and not noticing it, punching the head off of a Hollow through it's mask, and coming out of an explosion unscathed.
Tessai uses Kido several times during Ichigo's training. One of those times he uses a level 99 Binding incantation and does it flawlessly. It is pointed out during the series by Gin Ichimaru that a level 99 is extremely difficult to pull off and if done correctly the results will be incredible.
Tessai mentions hearing about Quincies 200 hundred years ago, meaning he is over 200 at the least, yet he looks to be in his late thirties early forties.
Tessai fights unarmed in every instance he has been shown fighting so far.