The Eccentric Family S01 E10 The Behind-the-Scenes Dealings of Souun Ebisugawa

The meaning of Kaisei's mysterious apology becomes clear as the Ebisugawa plot to boil Yaichirou in a hot pot is revealed on the day of the Nise-emon election. The day is also the anniversary of Soichirou's death, for which it turns out Souun was responsible.