From the Box Review: Otaki 1/48 Kawasaki Ki-100-1 Otsu Type 5 Tony Fighter

Kit No. OT2-15

By Michael Hays

The two major versions of the Japanese Army Air Force Ki-100 Type 5 radial-engine Tonys were created late in World War II as a happy consequence of the critical shortage of Ha-40 in-line engines needed for the Ki-61 Type 3 fighter airframes. Engineers hustled to redesign the Ki-61 fuselage to hold the fatter Ha-112 14-cylinder radial, and the result was a superior fighter capable of matching the challenge of American fighters then menacing mainland Japan. However, only about 118 teardrop-canopied Ki-100-1 Otsus and 272 of their Ki-100-1 Koh fastback cousins could be built before the end of hostilities.

This commonality of airframes among the Ki-61 and Ki-100 Tonys is represented in all the releases of Otaki’s 1/48 scale kits of these two important IJA fighters. All share the same wings, cockpit interiors, and tail planes.

Otaki’s offering represents the tear-drop canopy version of the Type 5, the Ki-100-1 Otsu. At least two different box top renderings were issued, both of the same kit (one called the plane the Ki-100 "Goshiki"). Arii later took over from Otaki and issued the same kit as the Ki-100 "Goshikisen," kit number A325. So what is said here applies to the Arii kit as well (unless new decals were provided). Furthermore, since most of the parts of Otaki’s Ki-100 are shared in common with its Ki-61 Type 3 kit, virtually everything said about building this model can be referenced for the earlier in-line engine Tony put out by Otaki!

This very simple injection-molded kit contains 44 light-gray parts attached to 3 trees. The parts are smooth and clean and feature relatively accurate engraved recessed panel lines in most locations. However, Otaki’s attempt to capture the rivet details so obvious on the Tony’s exterior surfaces goes a little overboard. Thousands of recessed but slightly oversized rivets have been pressed into all exterior surfaces of the kit. Although the pattern is tolerably accurate, the heavy recessed work will show more prominently than desired, especially on natural metal finish (NMF) aircraft. However, only a die-hard fanatic would attempt to fill these depressions, and they’re better left alone. Another alternative would be to lightly sand down the surfaces to help reduce the depth of the impressions. Even so, the pronounced rivet work will not be as noticeable if an aircraft with solid green or mottled green upper surfaces is chosen.

A single piece enclosed canopy also comes with the kit. By contemporary standards, it is slightly thick. It also suffers from tiny distortions within the clear styrene. Dipping it in floor wax, such as Future, may help, or a vacuformed replacement would be even better. There are no spare parts. However, a one-piece seated pilot figure is included, but his uniform is quite crude and does not represent contemporary standards of workmanship. Still it is a passable figure if you wish to place it in the cockpit.

The kit’s indigenous instruction sheet consists of a long single page in two panels printed in brown and white on both sides, all in Japanese. It sports a parts tree map, simple instructions represented in exploded-view drawings, and three-view profile drawings of the three aircraft represented by the kit decals. Although the ten-step drawings are clear enough to interpret without a knowledge of Japanese, fortunately for the English-speaking modeler a supplementary instruction sheet printed in English is included with the kit. This sheet contains a parts list, written step-by-step instructions for construction, and instructions for painting the three options presented. However, there are no illustrations.

The modeler has his choice to build one of three or more options. Choice one is a plane from the famous 244th Fighter Group in Japan during 1945. Three options of tail code colors permit the additional opportunity to represent the first, second, or third squadron in this group. Selection two represents the Ki-100 flown by a Captain Baba in the 5th Fighter Group in 1945. Choice three represents number 296 from the third squadron of the 59th Fighter Group in Japan in 1945. Again, three different colored tail codes permit the option of making a plane from the first or second squadron if desired. All three of the aircraft illustrated were painted IJA green over duralumin. The modeler may refer to the box top and sides for illustrations of these three aircraft in color.

The decal sheet contains generic markings unique to the three aircraft depicted, with optional colored tail codes to represent the different squadrons described above. The bright red hinomarus ("meatballs") appear with and without the white edge for optional selections. Only a couple of extra informational markings ("No step," or "No push"--in Japanese of course!) are included. The decals are in register, but a little thick by contemporary standards.

Construction is simple and straight forward. However, Otaki’s kits have been around for a number of years by now, and so they do not necessarily match the standards of workmanship now evident in more recent kits. Fortunately, the parts go together well with few problems. But the cockpit in Step One is going to provide perhaps the biggest challenge. This region is crude by modern standards. Except for the raised dials and gauges on the instrument panel, everything else is inaccurate to say the least. For example, the raised work and sparse details represented on the cockpit sides are both too shallow and fictional. The seat is totally wrong for Tonys. And the floor board with its raised details is a work of fantasy, too. To correct all these problems, I recommend you grind and sand off everything, then acquire any recent 1/48 scale Hasegawa kit of the Tony (kit numbers JT38 or JT44, or even JT14 or JT105) and scratch build a new interior using the Hasegawa parts as a guide. Furthermore, you can now use the Hasegawa kit to correct other problems on the exterior surfaces of the Otaki kit. Even if you use the kit parts as supplied, there is no gun sight, nor are the machine gun stocks represented in the dash. You can hide a lot of inaccuracies by simply installing the pilot in his seat. And it will help to drill out the lightning holes in the decking behind him. Good reference drawings of a Tony cockpit are extremely helpful here.

The wings for this kit are the typical two-part top halves that join with a single bottom piece. The wheel wells are represented, but they are extremely shallow, and the main gear doors do not match their contours! So if you wish to build a wheels up version, the gear doors will not close flush with the wing. The wells will need to be ground out and scratch-built doors substituted for the kit parts. The main landing gear legs are quite simple and the supplied wheels are not bulged. You may wish to add brake lines and make corrections to the interior panels of the main gear doors. Two pylons are supplied for the two fuel tanks included, but both the pylons and tanks lack the detail evident in the Hasegawa parts. A landing light is only represented in the port wing by engraved lines. You may wish to cut this area out and insert a clear plastic plug fashioned to represent the light. The same can be said as well for the wing tip formation lights. Also, both the wing and tail tips are slightly out of shape. They need to be a little more pointed, so use references or the Hasegawa parts as a guide to correct the shapes.

Otaki’s kit engine has a better representation of the cylinder banks than does Hasegawa’s counterpart. But the crankcase lacks detail and contains the push rods molded onto it. These parts can be improved with extra details and push rods made from stretched sprue.

The actuating rods on the tail and rudder are only represented by raised lines. Sanding these off and making replacements from stretched sprue or wire will enhance their appearance. Also, the exhaust stacks are accurately represented except they are too shallow. Making new ones of hollow wire or drilled out sprue can improve that area as well.

Most parts go together with little problem. However, there is an obvious mismatch where the tail joins with the fuselage. Filling and filing will be necessary here, and more filling will be needed where the wing joins with the fuselage. It’s probably a good idea to thin the prop blades a little bit, too.

Well, by modern standards this old kit shows its age. Although crude and inaccurate in places--especially the cockpit--, it is simple to build and can be handled by the novice modeler with no problem if no scratch building is desired. (In such cases, I recommend the pilot be placed in the cockpit to hide some of the more glaring faults located there.) When put together, the Otaki Ki-100's lines are basically accurate and all the major features required are there. Of course, with some extra effort, the more skilled modeler can correct the shortcomings, and the final product can still compare quite favorably with its newer Hasegawa competitors. It measures right on in scale, and when built and painted well, it will represent a good model of one of the premiere aircraft flown by the Imperial Japanese Army late in World War II.

Fortunately for the Allies, not many of these aircraft were encountered in Japan before hostilities ended. But when flown by capable pilots, the Ki-100 Type 5 Tonys proved to be a serious threat to the B-29s and to the Hellcat and Mustang pilots who had the unenviable challenge to confront them.


Rene J. Francillon, JAPANESE AIRCRAFT OF THE PACIFIC WAR, Putnam & Co., 1979 ed.


Edited, KAWASAKI Ki-61 (TONY), Paul Gaudette, Publisher, c. 1967.


Edited, KAWASAKI TYPE 3 "HIEN" & TYPE 5 ARMY FIGHTER (Ki-61 & Ki-100), The Maru Mechanic # 37, November, 1982.