The Ki-61-Ib (USA) is a premium American fighter. It has been in the game since the start of the Open Beta Test prior to Update 1.27. This aircraft is an American-captured version of the Ki-61-I otsu found in the Japanese tech tree.

Armed with four 12.7 mm Ho-103 machine guns and plenty of ammunition, the Ki-61-Ib is a more than capable fighter. As a continuation of the Japanese army tree, the Ki-61 is the successor of the earlier Ki-43 Hayabusa. The Hien is faster, has a higher rate of climb, and features a better armament. Utilize these three aspects when facing planes like the Ki-43. In realistic battles, one of the major advantages the Ki-61-Ib has is its climb rate. The stat card may be misleading, but this plane can reach altitudes no enemies will be close to (unless of course, the enemy is another Hien). This allows the Hien to choose when and where it wants to fight. Instead of simply "turning and burning" the Ki-61 is very good at energy fighting, or Boom & Zoom. Once at a high altitude the Hien pilot may choose to dive lower to attack an enemy. If the enemy is not destroyed on the first pass, it is recommended to climb sharply and gain altitude. By doing this, the Hien sets itself up for another attack while not being in the range of the enemy's guns.