I am in Prince of Tennis, others are training me while I am lying down

(No heroine in this article!) Takahashi Hikoichi travels through the world of Prince of Tennis, joins Rikkai University at the beginning, awakens the AFK system, and becomes stronger by lying down. "After one day of AFK, tennis skills are roughly mastered, and you have regional-level strength." "After one week of AFK, tennis skills are integrated and you have Kanto-level strength." "After one month of AFK, tennis skills are perfect and you have national-level strength." ... "After one year of AFK, tennis skills reach the pinnacle, you realize the unity of man and nature, create your own magic skills, and have world-class strength." While others train, he lies down! I thought he was a slacker, but I didn't expect his strength to increase instead of decrease. Everyone was shocked! He went all the way...