Various fighting styles are represented as techniques. Generally, there will be a level 2 technique named for the fighting style which gives some basic general bonuses, and a number of level 4/6 techniques which provide specialisations.
Each style will also have a techniques chain similar to sports and games. e.g.:
Karate (2), Karate Professional (4), Karate Expert (6), Karate Champion (8) and Karate Master (10).
These don't provide any bonuses as such, but if you are involved in a contest comparing your skill in that style, then the person with the highest level technique has an advantage. If you have none of the techniques, then you count as defaulting (your roll is halved).
For every higher level of technique, your critical chance is increased by +1. For every technique you are lower, your fumble chance is increased by +1.
e.g.: Alice has agility 4, brawl 10, and has Karate Professional (4). She's an expert fighter, but only has basic training in the school of Karate. Bob has agility 4, brawl 8 and has Karate Champion (8). He's not as good as Alice in all round fighting, but is well trained in the Karate style.
In a straight up fight (where they're both just trying to kick the shit out of each other), Alice would have the advantage. If they took part in a Karate competition however, where they're being marked on points for 'fighting the right way', Bob is two levels above Alice, so automatically 'wins' on attack/defence rolls of 19+. Alice will fumble on a 1-3. She'd also automatically win on a roll of '20', since she has the higher skill. If Alice was the champion, she'd automatically win on 18+.
Combat art which assumes a resisting enemy. Specialised in grapples, throws and feints as well as painful locks.
Offensive, not so good on defence. Extra damage and good at taking people down quickly.
General all-round combat art. Good at throws and grapples, though more focused on attack than Aikijutsu, but not as good at damaging as Karate.
Learn to mix everything you know together into a single art. There are no 'style' techniques. Winning is the only thing that counts.
Focus on stealth and assassination. Take people out quickly, not so good in a stand up fight. Also skill with shuriken, blowpipe and garrote.
Close fighting, parries and counter strikes. Also knife fighting, long staff and butterfly sword.
Specialised in the peasant weapons of Okinawa, e.g. Bo sticks, Jo sticks, Nunchuka and Sai.