Most self defense systems have some form of sparring within them. It can be used as a part of training that is designed to benefit the practitioner by getting them used to real time and contact! In the Takamatsuden arts I personally believe you can have some forms of sparring and should. I would agree with Chris though that you will find it hard to spar unless in a limited manner only using Takamatsuden technique. Hence why when you see off shoots or sparring within the Takamatsuden arts you will see them incorporate techniques more commonly found with heavy sparring or rolling arts like Muay Thai, Tae Kwon Do, Karate, Boxing, Brazilian Jiujitsu, etc. Why? Because when working in the sparring context those systems skill sets work very, very well! I would also agree with Chris that the Takamatsuden systems totally being geared towards a self preservation method with the idea of quick limited engagement do not necessarily parlay into a great sparring mentality and or technical execution with that goal in mind. Having said the above though I think anyone who studies within the Takamatsuden arts should spar and incorporate what is useful there. Yet, you have to have the understanding that sparring is not the same as fighting for your life on the street or in a war zone. Yet, sparring can make you mentally and physically tough and has it's place as an effective training tool!