Conformity? Ouch. I prefer to write twisted stories, so I can only think of themes like "tragedy", "war", "death", "doomsday", etc. But it might be better to save dark theme for October.
Speaking of which, if I were to think of a theme, I'd be too lazy and just make an upcoming event a theme, though I couldn't think of anything special in April except April Fools. (But the day has already passed.)
Or maybe "spring"? Or "sakura"? Which reminds me that there was some magical sakura tree that could grant you wishes, so maybe "magic" or "wish"?
No, I think we should stay away from seasonal themes after all, because they're getting old and boring.
After all that ramble (^), for some unknown reason the word "space" comes to my mind. Space as in outer space.
Yeah, I like it. "Space".