When his mother's friend, Kotone, becomes his tutor, Hiroyuki can't contain his excitement. It's no wonder, as her beautiful face and huge breasts stimulate his overflowing sexual desire even more... Then, Kotone notices his gaze and begins to tease him as if to vent her frustration. Since then, Kotone has come to visit him every now and then under the pretense of being a tutor, stimulating his lust and allowing him to enjoy the secret pleasure he can't get from his husband...