Guys I'm looking for this yaoi manga that's about a guy who's living with a yakuza who was...

Guys I'm looking for this yaoi manga that's about a guy who's living with a yakuza who was told to save him. He's been in love with the guy since, but the guy doesn't have eyes for anyone but his nephew I believe. But the real reason the yakuza guy was so cold was because of something his boss had told him once. I know the description is somewhat vague but if anyone knows I'd appreciate the help! Thanks!