Mika Tickets are an item featured in Killer Is Dead. They function similarly to Lollipop Chainsaw's Nick Tickets , but only in the sense that they allow for their respective characters' revival. When all of Mondo Zappa's health is depleted, the player has the option to either restart from the nearest checkpoint, or expend one Mika Ticket that will cause Mika to run to Mondo's aid and restart his heart, which is triggered by the player mashing the slash button. On success, Mondo will spring back to life with all of his health restored.
The process of mashing a button to revive your playable character may be a reference to killer7.