My brother's beautiful breasts wife

Koichi, whose mother had huge breasts, has always been only interested in women with big breasts, and was suspicious when his younger brother Yoshiyuki married the slender Yui. One day, Yoshiyuki goes on a business trip and accidentally catches a glimpse of Yui masturbating, who is too busy with her lonely body. Koichi's eyes widened not at the fact that Yui was masturbating, but at the sensitivity of Yui's beautiful breasts... The next day, Yoshiyuki returns from a business trip and quickly sees that the couple has fallen asleep, and Koichi crawls into Yui's futon...