Hello!

Shisui [Kotoamatsukami] was recently placed as the reward ninja in the Fireworks Event like what the guy said above me and was placed in few other events but these days, he's only seen in Treasure of the Sage Event. He will probably appear on other events in the future but that will depend on the Player's demand. The best way to do that is to suggest it in the weekly New Event Feedback Survey Form that is usually posted in the News Section. Thank you.

Hello!

I can't remember already but it is already months ago. He was the reward that you will get from using Fireworks, as well as from the milestones of your group's contribution. Basically, the free ninja of that event for its cycle. Thank you.