Onii to Tokkun♥

A young man finds himself in an unexpected situation when his older brother proposes an intense training session. The brother, eager to teach him a special kind of discipline, leads him into a private room where the lessons quickly take a more intimate turn. What starts as a simple exercise soon blurs the boundaries between instruction and desire.

The protagonist struggles to keep up with his brother's demanding methods, feeling both overwhelmed and strangely drawn to the experience. As the training progresses, the physical closeness and emotional tension escalate, forcing him to confront his own hidden feelings. The line between sibling affection and forbidden attraction becomes dangerously thin, setting the stage for a secret that could change their relationship forever.