Inside the body of a certain physically inactive person, the muscle cells had long lost their strength due to an unhealthy lifestyle. However, one day, an unexpected turn of events occurred—muscle training began, giving them a chance to revive! "What’s with those shredded abs? Are they a chocolate bar or what?!" Amid challenges like overwork, muscle soreness, and stress-induced muscle breakdown, the muscle cells push forward with the support of a rookie red blood cell, growing stronger day by day...!