Suu

There are gay characters. Also a straight character that is involved with a man. I don't count any of these as BL couples. The happy ending is between the male and female leads.

I would say one male lead is gay, and one male lead is straight. The main couple is between one male lead and the female lead. Ending is not exactly happy, but they do end it on a happy note (for the main couple)

As viewers, we know that DH is gay, but I don't think JH had absolute certainty. JH knows his brother had been keeping a secret and learns that his brother had a boyfriend. It was a logical and the correct conclusion for JH to arrive at, but what if DH wasn't gay? What if the "ex-boyfriend" was lying? What if DH had a different secret? What if DH was bi or pan? Since this is a drama, it is understandable why it was written this way

Yes, some families use generation names

2AM - Never Let You Go (죽어도 못보내)