Ore ga Kanojo o su Wake

Ooki Ryuuji once harbored feelings for someone, but that person married his brother and had a child. Over time, he suppressed these emotions. His niece, Rinka, runs away from home and comes to him. Having reached puberty, her figure has developed noticeably, with full breasts and thighs visible under her sailor uniform. Her face strongly resembles her mother's. Seeing this resemblance causes Ryuuji's buried feelings to resurface. His self-control erodes further after he accidentally discovers an aphrodisiac. He reflects on having known Rinka since her birth, her likeness to the woman he loved, and her mature physique, concluding he cannot restrain himself much longer.