Board Thread:Versus Debates/@comment-26005711-20151018173351/@comment-27074627-20151028160654

@GreatestSin, Koto's use on Itachi was unusual cause it was basically the same trick as with Ama sealing in Sasuke's left eye. In both cases Itachi programmed the technique to activate under certain circumstances. Sasuke used Ama on Tobi unintentionally, as did the crow with KA on Itachi, this happened because of Itachi's preparations. Ama is also a jutsu that does not need direct eye contact (although you need to focus your eye on the target(s), but not nessessary on their eyes), but was activated only after looking into Tobi's Sharingan directly. Crow's Koto worked nearly the same way - when Itachi's MS got into the field of view. The only difference between these two cases is the source of programmed technique. Ama was Itachi's own MS jutsu, he transcripted it into Sasuke's Sharingan, which did not posessed this technique at this time. KA is Shisui's technique and technique of his MS respectivelly. Shisui's left eye, which belonged to the crow, already contained it, all what Itachi had to do is to set it in the right way (that's why it would be incorrect to call this something like "Transcription Seal: Kotoamatsukami", cause there wasn't transcripted anything at all).