Originally posted by PeterR
The first technique of Tomiki's Koryu Goshin no Kata requires tori to initiate. The technique is right out of Budo Renshu by Ueshiba M.
To elaborate on that slightly, its a little like what Edward was describing, but in suwari-waza. Tori attacks with a back-fist strike to uke's face (essentially shomen-uchi), uke blocks the strike and tori takes ukes blocking arm through into an ikkyo pin. (Which we Shodokan types call 'oshi-taoshi', rather than 'ikkyo' btw.)