How does RUSH work during Co-Op?

For Co-Op battles, the RUSH bar is shared between the two players.
When both players have cleared a certain amount of Tsum Tsum, RUSH mode will activate for both players at the same time.
In RUSH mode, the damage dealt by your Tsum Tsum is increased.
There is no limit to the amount of time allocated to chain combos while in RUSH mode.