Bokura no Himitsu.

Seventeen-year-old Kamijou Naoya is a second-year high school student who has effortlessly cultivated an enviable reputation among his peers. Known widely as the "Refreshing Prince," he presents himself to the world with impeccable charm and grace, maintaining a flawless public image that conceals his true nature. Behind this carefully constructed facade, however, Naoya harbors a highly specific and closely guarded secret: a deep fascination with women's legs. For years, keeping this hidden quirk under wraps was relatively simple, largely because Naoya attended a strict all-boys academy where such temptations were entirely absent from his daily life. His princely persona remained completely unchallenged in an environment devoid of the very distraction he struggles to resist. Now, everything changes as his school makes the unprecedented decision to transition into a coeducational institution. With female students suddenly walking the same hallways and sitting in the same classrooms, Naoya finds his self-control tested like never before. The constant presence of his greatest temptation threatens to unravel the polished image he has spent years perfecting. As the newly integrated school year begins, he faces a daunting personal challenge: navigating his overwhelming urges while desperately trying to ensure his prestigious title remains intact.