First a tsuiwonasu is sealed with a blood seal, upon which he/she is ready for training at any time. While the pupil sleeps or during leisure time, genjutsu training episodes occur without warning. If the tsuiwonasu initiates training during sleeping hours, it occurs as a dream inserted into the normal rhythm of nightly REM sleep. Regular dreams are not interfered with as they are necessary to the normal healthy functioning of the brain and overall health. However, once these have taken place a genjutsu dream occurs that extends the normal hours of REM sleep.