When making repairs to any type of truck, you may consider using generic, off-brand parts, versus OEM parts. OEM (or original equipment manufacturing) parts are those made by companies authorized by the truck manufacturer. These OEM parts would then be the same parts that are used when the truck is built, and might only be sold by the dealer and certain authorized resellers.
While OEM parts can sometimes be more expensive than generic, off-brand parts, you need to consider the best choice for your truck's overall condition and lifespan, and not just the initial cost of repairs. Note a few considerations as to why you might avoid using generic parts and instead choose OEM Japanese truck parts for your Japanese truck's needed repairs.
Weight
Some parts are meant for lightweight trucks, so they are made with lightweight materials, such as toughened plastic or aluminium. This is opposed to steel or other metals, which can make a part much heavier overall.
Using a generic part that is made of steel or any heavier material may put undue stress on other parts under the truck's hood and can cause eventual damage to those other parts, if they're designed to be connected to something lighter. This extra weight can also mean putting added stress on the transmission and brakes of the truck, especially if you tow anything or store anything heavy in the truck. Don't assume that generic parts made of heavy steel or metal are automatically better for your truck, but choose a lightweight OEM part when available to avoid that added weight on other parts under the hood.
Electrical parts
You may not give much thought to the parts you use for electrical repairs on your truck, but these parts are very important for the overall performance of any vehicle. If you use poor-quality, generic parts for wiring, relays, switches, and the like, the parts of your truck that run on electricity may not get enough power. This can cause them to slow down or work intermittently, and it also puts added wear and tear on those parts, as they struggle to work with insufficient power. In turn, the engine could run without adequate fuel if the fuel pump doesn't work properly, or the engine could run hotter if the fan isn't functioning as it should. Don't assume that smaller electrical pieces can be low-quality and work as well as OEM parts, but invest in high-quality parts for all the electrical systems of your truck.