How about translate directly from the English requirements statement into SQL?
```
select movie_id
from genremap, genres
where genremap.genre_id == genres.genre_id
and genre_name == 'Romance'
INTERSECT
select movie_id
from genremap, genres
where genremap.genre_id == genres.genre_id
and genre_name == 'Comedy'
;
```
Also note that although pretty pictures may be pretty they are generally not useful. Textual description of the relevant tables is more environmentally friendly and wastes less energy and time.