Ecstas Online

Kakeru Meguri is a second-year student at Minami Myojin Public High School who plays the character named in the VRMMORPG <>. One day a player suddenly appear in front of his eyes, which turn out to be his popular beauty classmate Ririko Asagiri. She believes that if they defeat the demon king they will be able to return to the real world, in fact Kakeru knows that if a player dies in the game, their consciousness will disappear in the real world. To save an important person, Kakeru possesses the most powerful forbidden force, "Awaken Adult Mode".
note : Think about Masou Gakuen HxH feat SAO