Total War: SHOGUN 2

Total War: SHOGUN 2

MoSS Easy Install
How to recuit Sohei nagimaki troops?
Im playing a campaign as the uesugi and I have the tech where it says it allows you to recruit sohei nagmaki troops. however i cant seem to figure out where/how to recuit them. i have the top monastery. i dont even see the unit greyed out like i need certain resources or something. Any help would be appreciated