Sorry to be a spoilsport, but
O-Kagachi is a nonbo with Planeswalkers, and
Gideon Jura in particular. The ability will trigger only if the player attacked you, not if they attacked a planeswalker you control.
Here's the full ruling from
Gatherer:
Quote:
A player attacked you if that player declared a creature as an attacking creature and that creature is attacking you. If that player attacked only planeswalkers you control, that player didn’t attack you. If that player’s creatures were attacking you only because they were put onto the battlefield attacking or only because you were reselected as the player they were attacking, that player didn’t attack you.
In my opinion, the Kamigawa theme is awesome, so I hope you can make this deck work.

That may be on the janky side, but why not play the 5
Honden?
Also, I expected the deck to have a few fog effects (repeatable ones such as
Constant Mists or
Dawnstrider).