It is beyond confusing unless you read the story because of the intertwining storytelling of 5 generations over 80 plus years. I had to buy the book and read book it for this very reason-- will try to type a tree if it helps.    Not a typical K drama for certain.

SUNJA'S FAMILY -- 

1st generation Fisherman and Wife ;

2nd generation Hoonie(Sunja's father) and Sunja's Mother - Yangjin;

3rd generation SUNJA : then SUNJA {affair with HANSU] and marries ISAK

4th generation children of SUNJA - NOA (father HANSU) and MOZASU (father ISAK) -

5th generation SOLOMON (son of MOZASU ) NOA marries RISA (a Japanese woman) and has at least 3 nameless children.

SIDE CHARACTERS :

3rd generation YOSEB (Isak brother that helps SUNJA move to Japan
YOSEB'S childless wife - KYUNGHEE

4th generation: YUMI ( MOZASU WIFE - dies early) - MOZASU later develops a relationship with a Japanese woman (who he never marries).

5th generation side characters - HANA (daughter of SOLOMON"S father live in  Japanese mistress