While the vocals come from the series’ lead voice actors, Ai Fairouz and Kaito Ishikawa, the live-action video has bodybuilders Reika Saiki and Naotaka Yokokawa standing in for How Heavy Are the Dumbbells You Lift? main characters Hibiki and Machio.
But the song’s biggest gains in popularity might come from how many people, according to online comments, were inspired to start working out because of How Heavy Are the Dumbbells You Lift? and quickly put its theme song on their exercise playlist, drawing energy and inspiration from the way it makes exercise feel fun and inviting, especially when you pair it with scenes of Saiki and Yokokawa smiling and cheering each other on.
Anime in the “teenage girl starts a new hobby and is surprised to find how deep her passion is for it” genre are a dime a dozen, but 2019 weightlifting series How Heavy Are the Dumbbells You Lift? stood out from the pack.
And even though How Heavy Are the Dumbbells You Lift? has an obvious appreciation of beefy builds, “Onegai Muscle’s” final message, as expressed by its closing lyrics, is simply “You’re beautiful when you do your best,” which is a positive message worth hearing 115 million times.