Mario, the GM of a VR game, has set his new target on his childhood friend, Natsuume Saya, who is cheerful and popular with both men and women. Logging into the game as a female hero, Natsuume faces off against a tentacle-wielding monster, bewildered by her revealing bikini armor. However, she is quickly immobilized and experiences her first orgasm as the tentacles grope her entire body! When her armor melts and she is exposed, she is then penetrated for the first time.