The I-20 was a Type C-1 Class submarine, which was based on the Junsen-type, developed from the Type KD6. The C-1 Class was designed to carry the Ko-Hoteki midget submarine or Kaiten suicide torpedo. All 5 of the boats in this class took part in the Pearl Harbor attack on December 7, 1941. All of them launched midget submarines near the harbor entrance and they were never expected to return to the mother ship.
The kit was released for the 70th anniversary of the Pearl Harbor attack. There are examples of the midget submarines at the Naval Submarine School, Groton, Connecticut. While I was in Submarine School I was able to walk around them and take some pictures. In the end, the I-29 was finally
sunk by the USS Ellet in late August of 1943.
The kit comes with a really nice 16-page instruction booklet which leads you through the assembly process. The steps are pretty logical, and the assembly is well represented by pictures.