Mr. (Former) Yakuza is in Over His Head with Me, and I Can’t Escape Him.

The flirt who hits on her even during work is... a former yakuza!? Azusa is a doctor working as an occupational physician who takes her job seriously. Itsuki Sakuma, a handsome but suspicious guy who constantly annoys her during his evaluations! He's frivolous, aggressive, and mysterious... But then, he was the only one who noticed Azusa being terrified of her ex-fiance, who now stalks her. He said, "I'll protect you. I don't want you to be alone." He suddenly started looking so serious! She tries to discipline herself by telling herself to not get spoiled, but as he shows his gentlemen like personality, she can't help relying on him.... And that's when she saw the vivid traditional tattoos on him, and...!? He's a (former) yakuza who never let his prey escape from him, and now he goes all out for the love of his life. Let the show begin☆

(Source: MangaPlaza)