1) Roll Carnival event with coupons till you see Shisui there

2) Depending how you roll board with other rewards Shisui frags can be cheaper or more expensive still lets say 700 coupons average per frag

3) Spend just 130k+ coupons there to get 180 frags

Boom "ez" Shisui for you. It was good idea for people that saved over the year in last fuku deals, going for Shisui there + power from Fuku and some people could leap from having nothing to be relevant.

Remember 1 thing tho that with Ashura / Gaara and other new ninjas coming out getting Shisui in like mid 2023 seems pointless. Time of his glory is about to end.