[Omodume (Kushikatsu Koumei)] Omodume BOX 42 (Ryuuou no Oshigoto!) [Pangean]

A shogi master's discipline shatters the instant his student sister stops crying long enough to demand answers—namely, why won't he sleep with her? One crossed line in a love hotel snowballs fast, and before he can catch his breath, every one of Ai's friends has staked her claim, dragging him into sweat-soaked encounters where their competitive board-game instinct refuses to stay off the mattress. Now the girls keep each other in check, scrambling over one another for their turn and leaving him utterly, gloriously spent.