When the game first launched, it was primarily the GNW versions (I do remember looking at one of Kaizer's old videos that Jiraiya [Sannin Era] was one of the sign ins). The two Hebihime's were also sign ins. When I started playing in February 2017, it was GNW Kiba, followed by GNW Sai. Some other ninjas have been in there, as mentioned previously, Itachi [Anbu] was January 2018, Konohamaru [Shippuden], Orochimaru [Akatsuki], and Kushina Uzumaki. I'm all for these new low tier ninjas because now anyone can get the GNW versions from the NInja collection system.

Some of the monthly sign in also gave skillbooks for Sasuke and Sakura the month after the skillbreaks were released.