This article belongs to the Classic Continuity

Sensei is the judo teacher of Gwen Tennyson.

Appearance

He is an elderly Asian man with grey hair and a white judogi.

History

In Ben 10 Returns: Part 1, he was moderating a sparring match between Gwen and an unnamed student. He made a cameo in It's Not Easy Being Gwen.

Powers and Abilities

He's skilled enough in the fighting style of judo to be a black belt and to train and teach others.

Appearances

Alien Force

Season 1

• Ben 10 Returns: Part 1 (first appearance)

Ultimate Alien

Season 3

• It's Not Easy Being Gwen (first reappearance; cameo)

Human Characters
Prime Timeline
Tennyson Family	Ben Tennyson • Betty Jean Tennyson • Carl Tennyson • Clyde Fife • Frank Tennyson • Gordon Tennyson • Gwen Tennyson • Joel Tennyson • Ken Tennyson • Max Tennyson • Natalie Tennyson • Sandra Tennyson • Vera Tennyson
Osmosians	Cooper • Gaterboy • Kevin Levin • Porcupine
Hybrids	Alan Albright • Ester • Helen Wheels • Manny Armstrong • Pierce Wheels
Plumbers	Bel Biv Kaboom • Big Ed • Elliot • George Washington • Medics • Molly Gunther • Dr. Victor Valadis • Dr. Wes Green • Zorian
Forever Knights	foreverduke838 • Squire • Sir Winston
Actors	Abel North • Gwenettes • Jennifer Nocturne • Vilgax Actor
Government	Air Force Major General • Bald Police Officer • Mr. Bryson • Earl • Mr. Groff • Hugo • Ms. Liang • Ms. Locke • Mr. Liu • Mr. Mason • Mr. Molen • President • Red Coat • Colonel Rozum • Sheriff of Bellwood • Dr. Shueman • Special Extraterrestrial Containment Team • Lt. Steel • Mr. Wells • Yosemite Park Ranger
Magic	Bezel • Elsgood • Hex • Spellbinder • Thomas Jingles
News	Chet Rigby • Jimmy Jones • Steve Cummings • Vance Vetteroy • Wolf Blitzer
Professors and Scientists	Aniceto • Elena Valadis • Helena Xagliv • Dr. Kelly • Professor Paradox
Bellwood Residents	Alton Alabaster • Ben's Teacher (And Then There Were 10) • Ben's Teacher (Destroy All Aliens) • Bill Gacks • Dr. Borges • Carol Smith • Cash Murray • Cotton Candy Vendor • Counterman • Emily • Exasperated Guy • Ignacius Baumann • Jamie • Mrs. Jones • Jonesy • JT • Julie Yamamoto • Julius • Kevin's Mother • Madison • Madison's Father • Molly Suda • Natalie Alvarez • Pierce's Girlfriend • Mrs. Rheault • Sensei • Sparring Partner • Mr. Suda • Teej • Thaddeus J. Collins • Trina • Walt • Watchmaker • Mr. Webb • Mr. Yamamoto
Dairyville Residents	Digby Dairy Security Guard • Joan Maplewood • Todd Maplewood
Santa Mira Residents	Edna • Moe • Shem
Washington DC Residents	Regis • Roger • Sumo Slammer Collecting Boy
Other Humans	39th Street Bridge Gang • Amazing Alan • Andy • Barker • Barry • Bob • Brad • Cyclops Wrestler • Mr. Dodds • Donovan Grand Smith • Eddie Grand Smith • Edith • Erin • Eunice • Mrs. Fang • Fitz • Florence • Francisco Cortez • Fritz • Genaro • Gilbert • H.E. Grady • Harold • Harvey Hackett • Helio • Hervé • Hive • Hotel Guard • Howell Wainwright • Immovable Object • Jeff • Joe • Kai Green • Larry • Lawrence Wainright • Lobster-Arm Wrestler • Lucy • Mandy • Margie • Marty • Maureen Nocturne • Mildred • Mini-Failsafes • Oliver Thompson • Plumbiers • Dr. Randolph Pervis • Rich • Mrs. Rozum • Sandwich Vendor • Server • Shag Carpeting • Mr. Shaw • Shelby • Ship-It Clerk • Spectacled Wrestler • Mr. Simons • Tiffany • Tim Dean • Tyler • Valadis Laboratories Janitor • Mr. Zu
Alternate Dimensions/Timelines
Original Future Timeline	Ben Tennyson • Devlin Levin • Dr. Gwendolyn Tennyson • Gwendolyn Tennyson (Ben's Daughter) • J. Jonah Jones • Ken Tennyson • Kevin Levin • Max Tennyson
Race Against Time Timeline	Ben Tennyson • Carl Tennyson • Mrs. Carlyle • Cash Murray • Constantine Jacobs • Candace • Doris Dalton • Edward White • Mr. Engalls • Gwen Tennyson • Mr. Hawkins • Mr. Hubbard • Mr. Jennings • JT • Max Tennyson • Sandra Tennyson • Stephanie • Mr. Whittington
No Watch Timeline	Ben Tennyson • Gwen Tennyson • JT • Kevin Levin • Max Tennyson
Other Dimensions/Timelines	Ben 23 • Gwen 10 • Will Harangue (Mad Dimension)
Aborted Timelines
Time Heals Timeline	Ben Tennyson • Gwen Tennyson • Kevin Levin
Ultimate Alien Future Timeline	Ben Tennyson
Non-Canon
Gwen 10	Ben Tennyson • Gwen Tennyson • Max Tennyson
Goodbye and Good Riddance	Arnold • Ben Tennyson • Ben's Teacher • Carl Tennyson • Cash Murray • Gwen Tennyson • JT • Max Tennyson • Peterson • Sandra Tennyson
Books	Max Kane
Comics	Collector • Charlie Lien Ho • Charles • Dora Wrightson • Diaz • Dustin • Elena Valadis • Eliana • Grady • George Houston • Jane Marley • James • Leo • Lonnie • Lori • Mathieu • Patrick • President • Pietro • Sheila • Timothy • Tommy • Dr. Wrightson
Concept Characters
Crew	Judicator
Other Media
Generator Rex	Agent Six • Black Knight • Dr. Caesar Salazar • Diane Farrah • Dr. Gabriel Rylander • Dr. Peter Meechum • Providence • Rafael Salazar • Dr. Rebecca Holiday • Rex Salazar • Violeta Salazar • White Knight
The Secret Saturdays	Doc Saturday • Drew Saturday • Zak Saturday
MAD	Benjamin Franklin