If you're just dipping your toes into the world of steamy manga, I'd suggest starting with something that balances plot and spice without being overwhelming. 'Futari Ecchi' is a classic—it's got a sweet, newlywed couple exploring intimacy together, so it feels relatable and educational while still being fun. The art isn't overly exaggerated, which helps ease you in. Another great pick is 'Velvet Kiss,' which has a more dramatic storyline but keeps the heat level high without venturing into extreme territory.
For something lighter, 'Hapi Mari' mixes romance and smut with a marriage-of-convenience trope, so there's enough story to keep you hooked. Avoid jumping straight into hardcore stuff like 'Nana to Kaoru' unless you're ready for heavier BDSM themes. Take it slow, enjoy the buildup, and find what clicks for you—everyone's taste is different!