Dismayed by her recent weight gain, high school girl and food lover Hibiki Sakura joins Silverman Gym. The hordes of muscle men at the gym are intimidating, but Hibiki gives strength training a try after meeting the handsome trainer Machio Naruzo.

Machio explains why exercising causes you to gain both weight and muscle, and describes how to do a lat pulldown. Akemi lectures on the importance of dynamic stretching. Hibiki learns about Ayaka's family business.

Satomi Tachibana, one of Hibiki's teachers, comes to Silverman Gym to lose some weight. Can she hide her secret hobby from her students? Ayaka joins Hibiki and Akemi for lunch, and notices that something about Hibiki's bento feels off.

A crowded gym forces Hibiki and Akemi to use different equipment than usual. Ayaka joins them on a day when they have no choice but to train at home. And finally, the long-awaited beach day arrives.

Hibiki embarks on a special training regime in preparation for Sports Day. After the event is over, she hatches a plan to win the grand prize in the Silverman Gym raffle.

Determined to buy a home theater system, Hibiki enters the Silverman Gym arm wrestling tournament for the chance to win 100,000 yen. How will she fare against Gina, her Russian opponent? It turns out she has a lot to teach Hibiki and her friends.