The Type T-51a (No. 10) was the first of a new Japanese patrol boat type, known as the Type A (Kō/甲) torpedo boat (Heavy Torpedo boat). Subsequent standard small-sized patrol boats would be classified under Type B (Otsu/乙). Called into production and influenced by German S-Boots in 1941, the Japanese attempted to upscale their patrol boats from the previous Type T-1 at 20 tons to 80 tons. However, due to relatively low advancements in shipbuilding materials, especially for patrol boats, the entire vessel was constructed from steel and wood instead of light alloy. Additionally, the armament exceeded the planned weight, reaching over 90 tons. This failure to meet expectations led to the development of the variant Type T-51b (No. 11 - 17).

It was introduced during Update "Danger Zone" as a reward for Battle Pass: Season VIII, "Field Testing". Despite failing to meet the planned weight, the vessel is still operational and can be effectively used in two roles: either utilising the four torpedoes against slower, larger vessels or ambushing light boats with its rear-mounted anti-air twin 25 mm emplacement.