Judo
Judo (柔道 ,jūdō?),
meaning "gentle way", is a modern Japanese martial art (gendai budō)
and combat sport, that originated in Japan in the late nineteenth
century. Its most prominent feature is its competitive element,
where the object is to either throw one's opponent to the ground,
immobilize or otherwise subdue one's opponent with a grappling
manoeuvre, or force an opponent to submit by joint locking the elbow
or by executing a choke. Strikes and thrusts (by hands and feet) —
as well as weapons defences — are a part of judo, but only in
pre-arranged forms (kata)
and are not allowed in judo competition or free practice (randori).
Kata
Forms (kata) are pre-arranged patterns of attack and defence,
which in judo are practised with a partner for the purpose of
perfecting judo techniques. More specifically, their purposes
include illustrating the basic principles of judo, demonstrating the
correct execution of a technique, teaching the philosophical tenets
upon which judo is based, allowing for the practice of techniques
that are not allowed in competition, and to preserve ancient
techniques that are historically important but are no longer used in
contemporary judo
Randori
Judo emphasizes a free-style sparring, called randori, as one of
its main forms of training. Part of the combat time is spent
sparring standing up, called tachi-waza, and the other part on the
ground, called ne-waza. Sparring, even subject to safety rules, is
much more practically effective than only practicing techniques on
their own, which is what jujutsuka were used to doing. Using full
strength develops the muscles and cardio-vascular system on the
physical side of things, and it develops strategy and reaction time
on the mental side of things, and helps the practitioner learn to
use techniques against a resisting opponent. A common saying among
judoka is "The best training for judo is judo."
There are several types of sparring exercises, such as ju renshu
(both judoka attack in a very gentle way where no resistance is
applied); and kakari geiko (only one judoka attacks while the other
one relies solely on defensive and evasive techniques, but without
the use of sheer strength.)

Judo Calligraphy