No new heroines. He goes to the Twin Kingdoms because Aura is pregnant again, and he wants to secure a healer for the delivery, just in case, because he felt so powerless during Carlo-Zen's birth. He gets assigned a "guide" which is the daughter of a noble house who turns out to actually be a daughter of the royal family (Francesco's cousin, IIRC) who was exiled to a branch family because she does not have any magic. Aside from the Royal Family, there are also Four Ducal Houses, who are the descendants of the people who lived in the area when the Sharrow and Jillbel families first came from the North (from the same continent Freya is from). Zenji has to meet with representatives of the Ducal Houses, and they are all young, beautiful women. But Zenji is on his guard against all these women (and the "princess" is actually a legal loli), so I don't think anything is likely with them.
It's also been confirmed (to the audience, not to Zenji) by the Sharrow king that Bona is indeed a Honey Trap, but that she has no knowledge of this fact, as they decided that her natural charms would be more effective if she wasn't actually trying to seduce him. To be fair, they're probably right, which is another reason I consider Bona the next most likely Concubine Candidate.