One possible theme could be friendship. If Suha has a close group of friends in the story, their relationships and how they support each other could be a central theme.
I'm not sure specifically what'my suha side story' is. It could be a personal anecdote about someone named Suha. Maybe it's about a special experience or relationship related to Suha.
Yes. My Demon originated from a manhwa and has made certain changes to fit the medium of the adaptation. But the core elements and storylines are drawn from the manhwa source.
Well, you could try doing things he likes together to strengthen the bond. Also, showing appreciation and support for him can go a long way. Sometimes, small gestures of love and care can make a big difference.
One way could be to have heart-to-heart conversations regularly, listen to his perspective, and work on resolving any conflicts together. Surprising him with small gestures of love and support might also make a difference.