In Co-op mode, Yuuki's stats and passive do not change.
Yuuki's main Hyper, Angel Hand, does not visibly change in Co-op, but has a slightly different effect. The Hyper can only target players and not enemies, but otherwise functions the same as in Normal mode.
Yuuki's secondary Hyper, Devil Hand, has a different effect in Co-op. When used, one random non-KO'd enemy will instantly have their current HP reduced by 5. If the enemy's current HP is 5 or less, the enemy's current HP will instead be set to 1. The player gains 10 stars for each point of HP lost through this effect. On all odd-numbered chapters, this card will transform into Angel Hand.
Yuuki's passive and Hyper are unchanged in Bounty Hunt mode.
Yuuki's base stats give her 44 starting stars and a discount of -10% at shops.