Pact

From The World Ends With You - Wiki on Neoseeker

A pact is a bond forged between Players that must be done in order to survive the Noise. As shown by Beat's pact with Neku, Reapers can make pacts with Players, but in doing so, they abdicates their status as Reaper. Pacts can only truly be broken if one partner is erased by either Reapers or Noise.