Hello!

There is no specific amount for spending to get Shisui [Susano'o] from the Lucky Stars Wheel. The jackpot for that event is based on chances or the so-called RNG. You may spend 20 coupons or spend thousands of coupons without getting the jackpot. If you'll ask me, never spend in that event if you will only target the jackpot as it may disappoint you in the end but rather spend in that event and target the redeem items. Thank you.