ongoingTennis: I Become Strong by Idling at Rikkai
網球：人在立海大，掛機就變強
(No female lead in this story!) Takahashi Hikoichi transmigrated into the world of The Prince of Tennis. Starting off by joining Rikkai Dai, he awakened an AFK system, allowing him to become stronger just by lying down. "AFK for one day: tennis skills reach a rudimentary level, possessing regional-level strength." "AFK for one week: tennis skills become well-integrated, possessing Kanto-level strength." "AFK for one month: tennis skills reach perfection, possessing national-level strength." ... "AFK for one year: tennis skills reach the pinnacle, achieving harmony between man and nature, creating his own god-tier techniques, and possessing world-level strength." While others train, he lies flat! Everyone thought he was just a slacker, but they never expected his strength to increase rather than diminish. The crowd was absolutely shocked! He went on to become a legend of Rikkai Dai, ascending to the peak of the tennis world...