When the rank goes up, the stamina is fully recovered, and if the remaining amount of the stamina + the recovery amount exceeds the maximum value, the stamina temporarily exceeds the upper limit and the stamina is accumulated. For example, if there is 30 remaining stamina when the rank increases from 2 to 3, the stamina will be "65/35".
Natural recovery (1 stamina every 3 minutes) stops while the stamina exceeds the upper limit, and when the stamina is consumed and falls below the upper limit, natural recovery starts again.
Stamina that exceeds the upper limit can stack up to 999.
Every day, there will be up to two Bonus Stamina refilled on the main screen. Clicking on it grants 60 Stamina refill each, for a total for a total of extra 120 Stamina refill per day.