Shooto is probably the first mixed martial art that has always looked much like the mixed martial arts of today. At first it borrowed kicks, punches and grappling from other arts but those techniques have now evolved into techniques particular to shooto.
Lineage: The founder of Shooto is Sayama Satoru. Sayama was the original Tiger Mask of Japanese professional wrestling and the last live in student of the famous American wrestler Karl Gotch. Since then Sayama has moved on to develop a whole new kick boxing type martial art. Some of the original students of Sayama now teach shooto in gyms of their own and compete in both armature and professional fights several times a year.
Many teachers of different arts in Japan have different feelings towards today's mixed martial arts like Shooto. While the modern arts seem to show respect while many koryu people frown on the style. Many call it watered down budo, because it doesn't involve the spiritual training of the koryu nor the lethal techniques found in Koryu. One of my Koryu teachers, Otake Ritsuke, a famous koryu teacher in Japan once told me, " There is no competition in Budo, just fights to the death. Arts that fight for sport are not budo but brutality". Though I couldn't argue with that (and I wouldn't have, even if I could), I think there is a place for such training in the modern world. During the Edo periods and later, because the koryu arts were so dangerous, many of them refrained from actual sparring type practice and mostly only did form practice. But when they met with Kano's new brand of Judo (Bakumatsu/Meiji period), most of them could not compete with the artists that had frequent sparring practice. In the pre edo periods, koryu got plenty of practice on the battle field, I'm sure. But during the peaceful times of edo, this was not the case. I believe that shooto is a great way to hone your non-lethal skills in a close to realistic yet controlled environment.
In today's world, many of the lethal techniques in Koryu's will get you put in jail, even if they were used in self defense. So in that sense, I think mixed martial arts styles are also a good form of self defense. Not to mention a great work out, and a lot of fun!