Kuro is a pharm rep who's sent to a hospital to talk to Houjou, an anesthesiologist, but Houjoi hate pharma reps and rejects him. Instead of giving up Kuro seems to relish the challenge and does whatever he can to get close to Houjou, even accepting an invite to a conference where they end up screwing each other because they think the other person likes them.
Omoichigai ga Koi no Tane