Playing with a keyboard and mouse is for the main VR version, but it is achievable through specific community mods or emulation tools . The "Play Without VR" Review
The short answer is The official release is designed to be played exclusively with VR motion controllers. Nevertheless, through community tools and specific launch configurations, you can experience the game using standard keyboard and mouse input. Can You Play VR Kanojo Without a VR Headset? vr kanojo keyboard and mouse work