Non-transitory storage medium having stored therein game program, game apparatus, game system, and game method

A game system includes a mode switching unit switching a play mode between a one-player play mode and a two-player play mode, on the basis of at least one of first operation data from a left controller and second operation data from a right controller, and a control unit controlling a player character and a sub-player character in a virtual space. In the one-player play mode, the control unit switches an operation target between the player character and the sub-player character is set as an operation target, on the basis of the first operation data and the second operation data, and in the two-player play mode, the control unit controls the player character on the basis of the first operation data and controls the sub-player character on the basis of the second operation data.