Here are some websites where you can get inspiration for short intense workouts. Customize to Shorinji Kempo by focusing on explosiveness, speed and agility. Train in intervals rather than in long low-intensity rounds. Self defence requires more of these qualities than the qualities long distance training develop.
Jon Jones, one of the most successful in UFC, and also one of the most serious and sympathetic. Parts of his functional physical training. Borrow ideas and develop!
Manny Pacquiao train stomach and core in different ways. It seems to have some effect …
Speed and strength exercises from ice hockey practice
Boxing explosivity and core strength
(Ignore some nonsense into the clip, many interesting exercises are included)