I enjoy playing all the DD lines and think WG has done a great job making each nation's line distinct.
An IJN tactic which has really helped me is to FULLY embrace stealth - not just in remaining unseen but also not targeting an enemy until the exact moment I am ready to fire torps, then quickly targeting another ship after torps are away to lull my prey into a feeling of safety.
For example, let's say there are two BBs in the vicinity of each other, a Bismarck and an NC. I'll decide to make a run on the NC and will position my boat for the optimum torp angle on the NC, all the while with the Bismarck selected. The Bis will get the alert that he's being targeted even when he can't see me so he's on edge, maneuvering evasively. I'll usually wait until last possible moment when I can get close enough to the target before releasing torps, at which point I'll select the NC, fire off all my torps, then IMMEDIATELY switch back to the Bis. Many times the NC driver won't even notice the few seconds when he was selected and targeted and they will keep cruising along thinking they are safe, then BLAMMO.
This tactic is particularly effective at mid-tiers when driving the Kami.