18+ Shuuchuu Chiryou Shitsu

Makoto Sugiura has studied his whole life to become a doctor. He's looking for revenge on the doctor with a scalpel scar across his left hand. It was that doctor who is responsible for his sister's death. After finally being assigned to the right hospital, Makoto finds that the entire staff is involved in something suspicious. He decides to sleep his way to the truth, squeezing a confession out of one nurse after another until he makes his way to the top.

(Source: AniDB)