It is highly likely you are referring to one of the following two scenarios:

If you love the political intrigue and generational drama of Princess , check out these while we wait: Red River (Anatolia Story) Basara Goong (Princess Hours)

: Longtime readers often highlight the unique, traditional aesthetic of Han Seung-won’s art, which features highly detailed historical costuming. While the "old-school" manhwa style—characterized by elongated proportions and distinct facial features—can be polarizing for newer readers, it remains a hallmark of the series' identity. Reader Sentiment

: The tragic love story of Prince Biyon and his childhood friend Vee, which eventually spans three generations of royal turmoil and political conflict. Availability : Early volumes were published in English by Central Park Media

The confusion in search terms often stems here. "Nano Machine" is ongoing and releases new chapters weekly. If there is a "New" release by Han Seung-Won making waves currently, it is almost certainly related to Nano Machine (specifically the highly anticipated sequel or the current "Void" arc), rather than a new volume of a finished romance series.