You knew they were also locked when they asked to lock you up, but you had no idea they expected you to match the time they already had in their belt, and since she was Ace it wasn't difficult at all for her to last the 3 years she already had.
LF Mono Source: "my conscious is screaming to rape onei chan", 1girl, long hair, white hair, blush, eyes open, mouth open, from side, hand on others shoulder, hair between eyes, eyebrow visible through hair, long sleeve