Sensei is played by Simon greenall

Brain-Jitsu is a CBBC show which tests contestants to complete a set of challenges using different parts of their brains. After each challenge, one brainee is eliminated whilst the rest gain a higher level brain belt. The show is led and commentated by the Sensei, whilst the Shihan organises and watches over the tasks.

Between each level, contestants get the chance to prepare themselves for the challenge ahead in The Room Of Mental Nourishment. They are given a challenge to train the part of the brain needed for the next level. The brainees are given the choice whether to participate or not, but any extra training they do prepares them for the task ahead.