Since Gin-san was the White Yaksha, a major player in the Joi war, Hijikata orders a stakeout on Odd Jobs in order to find out if he's still connected to the Joi rebels. This stakeout mission lands at the feet of Inspector Yamazaki Sagaru.
If he sneaks into their 
private lives as an in-law,
إن تسلّل إلى حياتهم الخاصّة كصهر لهم
Si entra a sus vidas privadas como 
un familiar, nos conseguirá información.
Se ele entrar em suas vidas privadas,