Fighters-Were generally SINGLE ENGINE airplanes that intercepted bombers, other fighters performing escorts for the bombers, reconnaissance planes, or they escorted their own bombers, as well as going out on their own recon flights or strafing missions. All nations (all combatants) simply referred to them as "fighters."
A list of Japanese fighter planes of WW2:
(Model, Allied Code Name, and Japanese designation)
As a collective group the Martial Arts of Japan are referred to as Budo.
Budo includes iaido, karate, judo, and all the rest of the types of martial arts.
A master
There are Japanese martial arts. There are individuals that practice them. It would be a stereotype to think that all Japanese practice martial arts. The actual percentage is pretty small and probably is about the same as in the US.
Dojos. Dojo is Japanese for "place of the way". It can mean any formal training area, but typically it is associated with martial arts.
Only Japanese arts were allowed.
Martial Arts refers to the skills used in combat. Every country has martial arts and some originated in Japan, but not all of them.
karateka
You would teach in a martial arts school. The Japanese would call it a dojo.
"Sensei" means 'one who has gone before' and is usually associated with a teacher or mentor. You can call a martial arts instructor 'sensei' in Japanese.
"Gi" is a generic term for dress. In Japanese martial arts, gi is the term used to describe the uniform the class wears. The style of the gi can vary with the style of the martial art, but the term remains the same.
They are all martial arts from Asia. Kung fu is from China and karate is from Okinawa. Judo, kendo and aikido are Japanese.
Kendo
It is called "obi". In English, it may also be referred to as "obi sash" or "kimono sash".