Personal trainer is Sparta! Making a play because it was too erotic - Aika

Aika, a personal trainer, is tasked with helping her client Mizuno lose weight and build strength through intense physical training sessions. As the trainer, Aika pushes Mizuno to his limits, focusing on building his core strength and endurance. The central kink of this movie appears to be the domination and control Aika has over Mizuno during their training sessions, which may lead to a more intimate and submissive relationship.