is this the Mason gets his taste of his own medicine seeing them in other mans bed LAGS?
Viewing post in LSHT <===> LSHR Update Plans comments
Brother you don't understand the plot if you think Masuo is sleeping around at his own will.
To answer your question, no. He has the ring remember. If that breaks, Reiko will not be his girlfriend depending on the choice player makes. And it will be only implied that she is sleeping with Kunio. No animations. The reason being Masuo is amongst my dearest characters I've created.