After becoming lovers, you should still spend time with Tocchan in the agency. At some point, he should be asked to return back to his previous job, and MC can pick a choice in either letting him back or not.
I stayed with him all the days of the week, Sundays also. All the days in the year in the last playthrough, I only did the first job that is obligatory... All the other days I spent with him and called him all the nights... Even so, the scene didn't appear...
