Honeymoon, a vacation or trip was taken by a newly married couple.
After searching many things about marriage, Heero found about the honeymoon. On Star Web, there were also a few couples showing off about their honeymoon.
As an ancient man sealed from Dramonia, he felt there was a big difference tradition between Dramonia and Earth. So he had been searching for marriage stuff online to please his wife. The search led him to honeymoon.
He also found this honeymoon was a good thing to deepen the bond between him and his wife. Moreover, now he had another reason to go for a honeymoon trip, Han Ying. Even though the marriage between him and Han Ying was on paper only, she was still his sister-in-law.
Taking a break from work and went for a trip to change the atmosphere. It might be work to comfort Han Ying who currently missed her daughter. Actually, Heero's idea was to take Han Ying to her daughter, but Hong Yu denied his idea.