That’s right, Marcella who was first introduced in CHP4 is a descendant of Morinaga.
Her mother who was briefly seen in one of the visions in CHP19 is a Japanese and her father’s an Italian.

The truth is I originally planned to have her be an undercover kunoichi working for the Foot Clan.
At some point after her introduction, I changed my mind.
There are only so many teenagers in this story that can have super fighting skills before I start jumping the shark.