There are two types of hostages in the game.

If your character is hit by an enemy shot, or makes contact with an enemy android, the character will be frozen in place and remain there as a hostage until either he/she is saved or the next character becomes a hostage. In the latter case, the previous hostage will be lost.

Some stages have hostage(s) from the start of the stage. These remain even when your character is shot and becomes a hostage.

To save a hostage, touch and guide him/her out the exit. You can only guide one at a time. When saved, the hostages will then become usable in the next stage.

Remember, the hostage will be lost if you defeat all enemy androids before guiding him/her out the exit.